diff --git a/examples/GUI/VideoDemo.h b/examples/GUI/VideoDemo.h
index 2336156bc4..7f9ce3c23e 100644
--- a/examples/GUI/VideoDemo.h
+++ b/examples/GUI/VideoDemo.h
@@ -363,7 +363,7 @@ public:
         setPortraitOrientationEnabled (true);
     }
 
-    ~VideoDemo()
+    ~VideoDemo() override
     {
         curVideoComp->onPlaybackStarted = nullptr;
         curVideoComp->onPlaybackStopped = nullptr;
diff --git a/modules/juce_audio_devices/native/juce_android_Audio.cpp b/modules/juce_audio_devices/native/juce_android_Audio.cpp
index 3fa7399259..ecfa7b94fe 100644
--- a/modules/juce_audio_devices/native/juce_android_Audio.cpp
+++ b/modules/juce_audio_devices/native/juce_android_Audio.cpp
@@ -73,7 +73,7 @@ public:
     AndroidAudioIODevice (const String& deviceName)
         : AudioIODevice (deviceName, javaAudioTypeName),
           Thread ("audio"),
-          minBufferSizeOut (0), minBufferSizeIn (0), callback (0), sampleRate (0),
+          minBufferSizeOut (0), minBufferSizeIn (0), callback (nullptr), sampleRate (0),
           numClientInputChannels (0), numDeviceInputChannels (0), numDeviceInputChannelsAvailable (2),
           numClientOutputChannels (0), numDeviceOutputChannels (0),
           actualBufferSize (0), isRunning (false),
@@ -100,7 +100,7 @@ public:
               << sampleRate << " Hz; input chans: " << numDeviceInputChannelsAvailable);
     }
 
-    ~AndroidAudioIODevice()
+    ~AndroidAudioIODevice() override
     {
         close();
     }
@@ -196,7 +196,7 @@ public:
                                                                         (jint) (minBufferSizeOut * numDeviceOutputChannels * static_cast<int> (sizeof (int16))), MODE_STREAM)));
 
             const bool supportsUnderrunCount = (getAndroidSDKVersion() >= 24);
-            getUnderrunCount = supportsUnderrunCount ? env->GetMethodID (AudioTrack, "getUnderrunCount", "()I") : 0;
+            getUnderrunCount = supportsUnderrunCount ? env->GetMethodID (AudioTrack, "getUnderrunCount", "()I") : nullptr;
 
             int outputDeviceState = env->CallIntMethod (outputDevice, AudioTrack.getState);
             if (outputDeviceState > 0)
@@ -282,11 +282,11 @@ public:
     BigInteger getActiveOutputChannels() const override  { return activeOutputChans; }
     BigInteger getActiveInputChannels() const override   { return activeInputChans; }
     String getLastError() override                       { return lastError; }
-    bool isPlaying() override                            { return isRunning && callback != 0; }
+    bool isPlaying() override                            { return isRunning && callback != nullptr; }
 
     int getXRunCount() const noexcept override
     {
-        if (outputDevice != nullptr && getUnderrunCount != 0)
+        if (outputDevice != nullptr && getUnderrunCount != nullptr)
             return getEnv()->CallIntMethod (outputDevice, getUnderrunCount);
 
         return -1;
@@ -337,7 +337,7 @@ public:
                     DBG ("Audio read under-run! " << numRead);
                 }
 
-                jshort* const src = env->GetShortArrayElements (audioBuffer, 0);
+                jshort* const src = env->GetShortArrayElements (audioBuffer, nullptr);
 
                 for (int chan = 0; chan < inputChannelBuffer.getNumChannels(); ++chan)
                 {
@@ -380,7 +380,7 @@ public:
                 if (threadShouldExit())
                     break;
 
-                jshort* const dest = env->GetShortArrayElements (audioBuffer, 0);
+                jshort* const dest = env->GetShortArrayElements (audioBuffer, nullptr);
 
                 for (int chan = 0; chan < numDeviceOutputChannels; ++chan)
                 {
@@ -417,7 +417,7 @@ private:
     BigInteger activeOutputChans, activeInputChans;
     GlobalRef outputDevice, inputDevice;
     AudioBuffer<float> inputChannelBuffer, outputChannelBuffer;
-    jmethodID getUnderrunCount = 0;
+    jmethodID getUnderrunCount = nullptr;
 
     void closeDevices()
     {
diff --git a/modules/juce_audio_devices/native/juce_android_OpenSL.cpp b/modules/juce_audio_devices/native/juce_android_OpenSL.cpp
index dd3eb514c9..bc60ddcaec 100644
--- a/modules/juce_audio_devices/native/juce_android_OpenSL.cpp
+++ b/modules/juce_audio_devices/native/juce_android_OpenSL.cpp
@@ -340,7 +340,7 @@ public:
                     auto status = (*config)->AcquireJavaProxy (config, /*SL_ANDROID_JAVA_PROXY_ROUTING*/1,
                                                                &audioRoutingJni);
 
-                    if (status == SL_RESULT_SUCCESS && audioRoutingJni != 0)
+                    if (status == SL_RESULT_SUCCESS && audioRoutingJni != nullptr)
                         javaProxy = GlobalRef (LocalRef<jobject>(getEnv()->NewLocalRef (audioRoutingJni)));
                 }
             }
@@ -662,7 +662,7 @@ public:
                     }
 
                     const bool supportsUnderrunCount = (getAndroidSDKVersion() >= 24);
-                    getUnderrunCount = supportsUnderrunCount ? getEnv()->GetMethodID (AudioTrack, "getUnderrunCount", "()I") : 0;
+                    getUnderrunCount = supportsUnderrunCount ? getEnv()->GetMethodID (AudioTrack, "getUnderrunCount", "()I") : nullptr;
                 }
             }
         }
@@ -727,7 +727,7 @@ public:
 
         int getXRunCount() const noexcept override
         {
-            if (player != nullptr && player->javaProxy != nullptr && getUnderrunCount != 0)
+            if (player != nullptr && player->javaProxy != nullptr && getUnderrunCount != nullptr)
                 return getEnv()->CallIntMethod (player->javaProxy, getUnderrunCount);
 
             return -1;
@@ -783,7 +783,7 @@ public:
         std::unique_ptr<OpenSLQueueRunnerPlayer<T>> player;
         std::unique_ptr<OpenSLQueueRunnerRecorder<T>> recorder;
         Atomic<int> guard;
-        jmethodID getUnderrunCount = 0;
+        jmethodID getUnderrunCount = nullptr;
     };
 
     //==============================================================================
@@ -810,7 +810,7 @@ public:
         ignoreUnused (success);
     }
 
-    ~OpenSLAudioIODevice()
+    ~OpenSLAudioIODevice() override
     {
         close();
     }
diff --git a/modules/juce_audio_devices/native/juce_ios_Audio.cpp b/modules/juce_audio_devices/native/juce_ios_Audio.cpp
index 8a915cb1af..23da27eaa9 100644
--- a/modules/juce_audio_devices/native/juce_ios_Audio.cpp
+++ b/modules/juce_audio_devices/native/juce_ios_Audio.cpp
@@ -216,7 +216,7 @@ class iOSAudioIODeviceType  : public AudioIODeviceType,
 {
 public:
     iOSAudioIODeviceType();
-    ~iOSAudioIODeviceType();
+    ~iOSAudioIODeviceType() override;
 
     void scanForDevices() override;
     StringArray getDeviceNames (bool) const override;
@@ -262,7 +262,7 @@ struct iOSAudioIODevice::Pimpl      : public AudioPlayHead,
         sessionHolder->activeDevices.add (this);
     }
 
-    ~Pimpl()
+    ~Pimpl() override
     {
         sessionHolder->activeDevices.removeFirstMatchingValue (this);
 
diff --git a/modules/juce_audio_utils/native/juce_android_BluetoothMidiDevicePairingDialogue.cpp b/modules/juce_audio_utils/native/juce_android_BluetoothMidiDevicePairingDialogue.cpp
index 664b4837e3..c981ad769d 100644
--- a/modules/juce_audio_utils/native/juce_android_BluetoothMidiDevicePairingDialogue.cpp
+++ b/modules/juce_audio_utils/native/juce_android_BluetoothMidiDevicePairingDialogue.cpp
@@ -421,7 +421,7 @@ public:
         enterModalState (true, exitCallback.release(), true);
     }
 
-    ~BluetoothMidiSelectorOverlay()
+    ~BluetoothMidiSelectorOverlay() override
     {
         AndroidBluetoothMidiInterface::startStopScan (false);
     }
diff --git a/modules/juce_audio_utils/native/juce_ios_BluetoothMidiDevicePairingDialogue.mm b/modules/juce_audio_utils/native/juce_ios_BluetoothMidiDevicePairingDialogue.mm
index 0b2e003ae9..eccb0b82e2 100644
--- a/modules/juce_audio_utils/native/juce_ios_BluetoothMidiDevicePairingDialogue.mm
+++ b/modules/juce_audio_utils/native/juce_ios_BluetoothMidiDevicePairingDialogue.mm
@@ -61,7 +61,7 @@ public:
         enterModalState (true, exitCallback.release(), true);
     }
 
-    ~BluetoothMidiSelectorOverlay()
+    ~BluetoothMidiSelectorOverlay() override
     {
         nativeSelectorComponent.setView (nullptr);
         [controller release];
@@ -126,7 +126,7 @@ bool BluetoothMidiDevicePairingDialogue::open (ModalComponentManager::Callback*
 
 bool BluetoothMidiDevicePairingDialogue::isAvailable()
 {
-    return NSClassFromString ([NSString stringWithUTF8String: "CABTMIDICentralViewController"]) != nil;
+    return NSClassFromString (@"CABTMIDICentralViewController") != nil;
 }
 
 } // namespace juce
diff --git a/modules/juce_blocks_basics/littlefoot/juce_LittleFootRunner.h b/modules/juce_blocks_basics/littlefoot/juce_LittleFootRunner.h
index f36e46078b..aca029fe8c 100644
--- a/modules/juce_blocks_basics/littlefoot/juce_LittleFootRunner.h
+++ b/modules/juce_blocks_basics/littlefoot/juce_LittleFootRunner.h
@@ -174,7 +174,7 @@ struct NativeFunction
         jassert (slash > 0); // The slash can't be the first character in this string!
         jassert (nameAndArgTypes[slash + 1] != 0);  // The slash must be followed by a return type character
         jassert (String (nameAndArgTypes).substring (0, slash).containsOnly ("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_"));
-        jassert (! String ("0123456789").containsChar (nameAndArgTypes[0]));
+        jassert (! String ("0123456789").containsChar (String (nameAndArgTypes)[0]));
         jassert (String (nameAndArgTypes).substring (slash + 1).containsOnly ("vifb"));
         jassert (String (nameAndArgTypes).substring (slash + 2).containsOnly ("ifb")); // arguments must only be of these types
 
diff --git a/modules/juce_core/misc/juce_ConsoleApplication.cpp b/modules/juce_core/misc/juce_ConsoleApplication.cpp
index 238360ef53..bf3bf5c737 100644
--- a/modules/juce_core/misc/juce_ConsoleApplication.cpp
+++ b/modules/juce_core/misc/juce_ConsoleApplication.cpp
@@ -111,7 +111,7 @@ bool ArgumentList::Argument::isShortOption (char option) const
 {
     jassert (option != '-'); // this is probably not what you intended to pass in
 
-    return isShortOption() && text.containsChar (option);
+    return isShortOption() && text.containsChar (String (option)[0]);
 }
 
 bool ArgumentList::Argument::operator== (StringRef wildcard) const
diff --git a/modules/juce_core/native/juce_android_Files.cpp b/modules/juce_core/native/juce_android_Files.cpp
index 115dba7d40..4163c59a55 100644
--- a/modules/juce_core/native/juce_android_Files.cpp
+++ b/modules/juce_core/native/juce_android_Files.cpp
@@ -89,7 +89,7 @@ static File getWellKnownFolder (const char* folderId)
     auto* env = getEnv();
     auto fieldId = env->GetStaticFieldID (AndroidEnvironment, folderId, "Ljava/lang/String;");
 
-    if (fieldId == 0)
+    if (fieldId == nullptr)
     {
         // unknown field in environment
         jassertfalse;
@@ -194,7 +194,7 @@ public:
         auto* env = getEnv();
         LocalRef<jobject> contentResolver (env->CallObjectMethod (getAppContext().get(), AndroidContext.getContentResolver));
 
-        if (contentResolver == 0)
+        if (contentResolver == nullptr)
             return {};
 
         auto filename = getStringUsingDataColumn ("_display_name", env, uri, contentResolver);
@@ -298,7 +298,7 @@ private:
             auto* env = getEnv();
             static jmethodID m = (env->GetMethodID (AndroidContext, "getExternalFilesDirs",
                                                     "(Ljava/lang/String;)[Ljava/io/File;"));
-            if (m == 0)
+            if (m == nullptr)
                 return {};
 
             auto paths = convertFileArray (LocalRef<jobject> (env->CallObjectMethod (getAppContext().get(), m, nullptr)));
@@ -406,7 +406,7 @@ private:
             return {};
         }
 
-        if (cursor == 0)
+        if (cursor == nullptr)
             return {};
 
         String fileName;
@@ -439,7 +439,7 @@ struct AndroidContentUriOutputStream :  public OutputStream
     {
     }
 
-    ~AndroidContentUriOutputStream()
+    ~AndroidContentUriOutputStream() override
     {
         stream.callVoidMethod (AndroidOutputStream.close);
     }
@@ -484,7 +484,7 @@ OutputStream* juce_CreateContentURIOutputStream (const URL& url)
 {
     auto stream = AndroidContentUriResolver::getStreamForContentUri (url, false);
 
-    return (stream.get() != 0 ? new AndroidContentUriOutputStream (std::move (stream)) : nullptr);
+    return (stream.get() != nullptr ? new AndroidContentUriOutputStream (std::move (stream)) : nullptr);
 }
 
 //==============================================================================
@@ -676,7 +676,7 @@ private:
 
 void FileOutputStream::flushInternal()
 {
-    if (fileHandle != 0)
+    if (fileHandle != nullptr)
     {
         if (fsync (getFD (fileHandle)) == -1)
             status = getResultForErrno();
diff --git a/modules/juce_core/native/juce_android_JNIHelpers.cpp b/modules/juce_core/native/juce_android_JNIHelpers.cpp
index ea41e53e22..89d70ca753 100644
--- a/modules/juce_core/native/juce_android_JNIHelpers.cpp
+++ b/modules/juce_core/native/juce_android_JNIHelpers.cpp
@@ -116,7 +116,7 @@ struct SystemJavaClassComparator
 
 //==============================================================================
 JNIClassBase::JNIClassBase (const char* cp, int classMinSDK, const void* bc, size_t n)
-    : classPath (cp), byteCode (bc), byteCodeSize (n), minSDK (classMinSDK), classRef (0)
+    : classPath (cp), byteCode (bc), byteCodeSize (n), minSDK (classMinSDK), classRef (nullptr)
 {
     SystemJavaClassComparator comparator;
 
@@ -162,13 +162,13 @@ void JNIClassBase::initialise (JNIEnv* env)
             LocalRef<jobject> defaultClassLoader (env->CallStaticObjectMethod (JavaClassLoader, JavaClassLoader.getSystemClassLoader));
             tryLoadingClassWithClassLoader (env, defaultClassLoader.get());
 
-            if (classRef == 0)
+            if (classRef == nullptr)
             {
                 for (auto& byteCodeLoader : byteCodeLoaders)
                 {
                     tryLoadingClassWithClassLoader (env, byteCodeLoader.get());
 
-                    if (classRef != 0)
+                    if (classRef != nullptr)
                         break;
                 }
 
@@ -234,10 +234,10 @@ void JNIClassBase::initialise (JNIEnv* env)
             }
         }
 
-        if (classRef == 0)
+        if (classRef == nullptr)
             classRef = (jclass) env->NewGlobalRef (LocalRef<jobject> (env->FindClass (classPath)));
 
-        jassert (classRef != 0);
+        jassert (classRef != nullptr);
         initialiseFields (env);
     }
 }
@@ -253,7 +253,7 @@ void JNIClassBase::tryLoadingClassWithClassLoader (JNIEnv* env, jobject classLoa
     if (jthrowable exception = env->ExceptionOccurred ())
     {
         env->ExceptionClear();
-        classObj = 0;
+        classObj = nullptr;
     }
 
     // later versions of Android don't throw at all, so re-check the object
@@ -263,7 +263,7 @@ void JNIClassBase::tryLoadingClassWithClassLoader (JNIEnv* env, jobject classLoa
 
 void JNIClassBase::release (JNIEnv* env)
 {
-    if (classRef != 0)
+    if (classRef != nullptr)
         env->DeleteGlobalRef (classRef);
 }
 
@@ -284,28 +284,28 @@ void JNIClassBase::releaseAllClasses (JNIEnv* env)
 jmethodID JNIClassBase::resolveMethod (JNIEnv* env, const char* methodName, const char* params)
 {
     jmethodID m = env->GetMethodID (classRef, methodName, params);
-    jassert (m != 0);
+    jassert (m != nullptr);
     return m;
 }
 
 jmethodID JNIClassBase::resolveStaticMethod (JNIEnv* env, const char* methodName, const char* params)
 {
     jmethodID m = env->GetStaticMethodID (classRef, methodName, params);
-    jassert (m != 0);
+    jassert (m != nullptr);
     return m;
 }
 
 jfieldID JNIClassBase::resolveField (JNIEnv* env, const char* fieldName, const char* signature)
 {
     jfieldID f = env->GetFieldID (classRef, fieldName, signature);
-    jassert (f != 0);
+    jassert (f != nullptr);
     return f;
 }
 
 jfieldID JNIClassBase::resolveStaticField (JNIEnv* env, const char* fieldName, const char* signature)
 {
     jfieldID f = env->GetStaticFieldID (classRef, fieldName, signature);
-    jassert (f != 0);
+    jassert (f != nullptr);
     return f;
 }
 
@@ -440,10 +440,10 @@ int getAndroidSDKVersion()
         auto* env = getEnv();
 
         auto buildVersion = env->FindClass ("android/os/Build$VERSION");
-        jassert (buildVersion != 0);
+        jassert (buildVersion != nullptr);
 
         auto sdkVersionField = env->GetStaticFieldID (buildVersion, "SDK_INT", "I");
-        jassert (sdkVersionField != 0);
+        jassert (sdkVersionField != nullptr);
 
         return env->GetStaticIntField (buildVersion, sdkVersionField);
     }();
@@ -581,7 +581,7 @@ void FragmentOverlay::onRequestPermissionsResultNative (JNIEnv* env, jobject, jl
 
         if (n > 0)
         {
-            auto* data = env->GetIntArrayElements (jGrantResults, 0);
+            auto* data = env->GetIntArrayElements (jGrantResults, nullptr);
 
             for (int i = 0; i < n; ++i)
                 grantResults.add (data[i]);
diff --git a/modules/juce_core/native/juce_android_JNIHelpers.h b/modules/juce_core/native/juce_android_JNIHelpers.h
index 4af5b85304..389b48ef84 100644
--- a/modules/juce_core/native/juce_android_JNIHelpers.h
+++ b/modules/juce_core/native/juce_android_JNIHelpers.h
@@ -31,18 +31,18 @@ template <typename JavaType>
 class LocalRef
 {
 public:
-    explicit inline LocalRef() noexcept                 : obj (0) {}
+    explicit inline LocalRef() noexcept                 : obj (nullptr) {}
     explicit inline LocalRef (JavaType o) noexcept      : obj (o) {}
     inline LocalRef (const LocalRef& other) noexcept    : obj (retain (other.obj)) {}
-    inline LocalRef (LocalRef&& other) noexcept         : obj (0) { std::swap (obj, other.obj); }
+    inline LocalRef (LocalRef&& other) noexcept         : obj (nullptr) { std::swap (obj, other.obj); }
     ~LocalRef()                                         { clear(); }
 
     void clear()
     {
-        if (obj != 0)
+        if (obj != nullptr)
         {
             getEnv()->DeleteLocalRef (obj);
-            obj = 0;
+            obj = nullptr;
         }
     }
 
@@ -69,7 +69,7 @@ private:
 
     static JavaType retain (JavaType obj)
     {
-        return obj == 0 ? 0 : (JavaType) getEnv()->NewLocalRef (obj);
+        return obj == nullptr ? nullptr : (JavaType) getEnv()->NewLocalRef (obj);
     }
 };
 
@@ -77,21 +77,21 @@ private:
 class GlobalRef
 {
 public:
-    inline GlobalRef() noexcept                             : obj (0) {}
+    inline GlobalRef() noexcept                             : obj (nullptr) {}
     inline explicit GlobalRef (const LocalRef<jobject>& o)  : obj (retain (o.get(), getEnv())) {}
     inline explicit GlobalRef (const LocalRef<jobject>& o, JNIEnv* env)  : obj (retain (o.get(), env)) {}
     inline GlobalRef (const GlobalRef& other)           : obj (retain (other.obj, getEnv())) {}
-    inline GlobalRef (GlobalRef && other) noexcept      : obj (0) { std::swap (other.obj, obj); }
+    inline GlobalRef (GlobalRef && other) noexcept      : obj (nullptr) { std::swap (other.obj, obj); }
     ~GlobalRef()                                             { clear(); }
 
 
-    inline void clear()                                 { if (obj != 0) clear (getEnv()); }
+    inline void clear()                                 { if (obj != nullptr) clear (getEnv()); }
     inline void clear (JNIEnv* env)
     {
-        if (obj != 0)
+        if (obj != nullptr)
         {
             env->DeleteGlobalRef (obj);
-            obj = 0;
+            obj = nullptr;
         }
     }
 
@@ -147,11 +147,11 @@ public:
 
 private:
     //==============================================================================
-    jobject obj = 0;
+    jobject obj = nullptr;
 
     static inline jobject retain (jobject obj, JNIEnv* env)
     {
-        return obj == 0 ? 0 : env->NewGlobalRef (obj);
+        return obj == nullptr ? nullptr : env->NewGlobalRef (obj);
     }
 };
 
@@ -193,7 +193,7 @@ private:
     size_t byteCodeSize;
 
     int minSDK;
-    jclass classRef = 0;
+    jclass classRef = nullptr;
 
     static Array<JNIClassBase*>& getClasses();
     void initialise (JNIEnv*);
@@ -755,7 +755,7 @@ namespace
 {
     inline String juceString (JNIEnv* env, jstring s)
     {
-        if (s == 0)
+        if (s == nullptr)
             return {};
 
         const char* const utf8 = env->GetStringUTFChars (s, nullptr);
@@ -889,7 +889,7 @@ private:
 //==============================================================================
 struct SurfaceHolderCallback    : AndroidInterfaceImplementer
 {
-    virtual ~SurfaceHolderCallback() {}
+    virtual ~SurfaceHolderCallback() override = default;
 
     virtual void surfaceChanged (LocalRef<jobject> holder, int format, int width, int height) = 0;
     virtual void surfaceCreated (LocalRef<jobject> holder) = 0;
diff --git a/modules/juce_core/native/juce_android_Network.cpp b/modules/juce_core/native/juce_android_Network.cpp
index 375b5fbc49..83e8522d0a 100644
--- a/modules/juce_core/native/juce_android_Network.cpp
+++ b/modules/juce_core/native/juce_android_Network.cpp
@@ -297,7 +297,7 @@ public:
 
         const ScopedLock lock (createStreamLock);
 
-        if (stream != 0)
+        if (stream != nullptr)
         {
             stream.callVoidMethod (HTTPStream.release);
             stream.clear();
@@ -333,7 +333,7 @@ public:
             if (isPost)
                 WebInputStream::createHeadersAndPostData (url, headers, postData);
 
-            jbyteArray postDataArray = 0;
+            jbyteArray postDataArray = nullptr;
 
             if (postData.getSize() > 0)
             {
@@ -348,7 +348,7 @@ public:
             jassert (Thread::getCurrentThread() != nullptr);
 
             jintArray statusCodeArray = env->NewIntArray (1);
-            jassert (statusCodeArray != 0);
+            jassert (statusCodeArray != nullptr);
 
             {
                 const ScopedLock lock (createStreamLock);
@@ -367,18 +367,18 @@ public:
                                                                                         javaString (httpRequest).get())));
             }
 
-            if (stream != 0 && ! stream.callBooleanMethod (HTTPStream.connect))
+            if (stream != nullptr && ! stream.callBooleanMethod (HTTPStream.connect))
                 stream.clear();
 
-            jint* const statusCodeElements = env->GetIntArrayElements (statusCodeArray, 0);
+            jint* const statusCodeElements = env->GetIntArrayElements (statusCodeArray, nullptr);
             statusCode = statusCodeElements[0];
             env->ReleaseIntArrayElements (statusCodeArray, statusCodeElements, 0);
             env->DeleteLocalRef (statusCodeArray);
 
-            if (postDataArray != 0)
+            if (postDataArray != nullptr)
                 env->DeleteLocalRef (postDataArray);
 
-            if (stream != 0)
+            if (stream != nullptr)
             {
                 StringArray headerLines;
 
@@ -547,12 +547,12 @@ static Array<InterfaceInfo> findIPAddresses (int dummySocket)
         if (item.ifr_addr.sa_family == AF_INET)
         {
             InterfaceInfo info;
-            info.interfaceAddress = makeAddress ((const sockaddr_in*) &item.ifr_addr);
+            info.interfaceAddress = makeAddress (reinterpret_cast<const sockaddr_in*> (&item.ifr_addr));
 
             if (! info.interfaceAddress.isNull())
             {
                 if (ioctl (dummySocket, SIOCGIFBRDADDR, &item) == 0)
-                    info.broadcastAddress = makeAddress ((const sockaddr_in*) &item.ifr_broadaddr);
+                    info.broadcastAddress = makeAddress (reinterpret_cast<const sockaddr_in*> (&item.ifr_broadaddr));
 
                 result.add (info);
             }
diff --git a/modules/juce_core/native/juce_android_RuntimePermissions.cpp b/modules/juce_core/native/juce_android_RuntimePermissions.cpp
index 8d8fa14638..d4b1acf03b 100644
--- a/modules/juce_core/native/juce_android_RuntimePermissions.cpp
+++ b/modules/juce_core/native/juce_android_RuntimePermissions.cpp
@@ -95,7 +95,7 @@ struct PermissionsRequest
 struct PermissionsOverlay   : FragmentOverlay
 {
     PermissionsOverlay (CriticalSection& cs) : overlayGuard (cs) {}
-    ~PermissionsOverlay() {}
+    ~PermissionsOverlay() override = default;
 
     struct PermissionResult
     {
@@ -175,7 +175,7 @@ struct PermissionsOverlay   : FragmentOverlay
 
                 // this code should only be reached for SDKs >= 23, so this method should be
                 // be available
-                jassert(requestPermissionsMethodID != 0);
+                jassert(requestPermissionsMethodID != nullptr);
 
                 env->CallVoidMethod (getNativeHandle(), requestPermissionsMethodID, jPermissionsArray.get (), 0);
             }
diff --git a/modules/juce_core/native/juce_android_Threads.cpp b/modules/juce_core/native/juce_android_Threads.cpp
index ec1135b163..1b72686dda 100644
--- a/modules/juce_core/native/juce_android_Threads.cpp
+++ b/modules/juce_core/native/juce_android_Threads.cpp
@@ -113,7 +113,7 @@ public:
         checkActivityIsMain (androidApkContext);
     }
 
-    ~JuceActivityWatcher()
+    ~JuceActivityWatcher() override
     {
         LocalRef<jobject> appContext (getAppContext());
 
diff --git a/modules/juce_core/native/juce_mac_Network.mm b/modules/juce_core/native/juce_mac_Network.mm
index 7c3104d85f..d86baf45b6 100644
--- a/modules/juce_core/native/juce_mac_Network.mm
+++ b/modules/juce_core/native/juce_mac_Network.mm
@@ -425,7 +425,8 @@ struct BackgroundDownloadTask  : public URL::DownloadTask
         DelegateClass::setState (delegate, this);
 
         activeSessions.set (uniqueIdentifier, this);
-        NSMutableURLRequest* request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:juceStringToNS (urlToUse.toString (true))]];
+        auto nsUrl = [NSURL URLWithString: juceStringToNS (urlToUse.toString (true))];
+        NSMutableURLRequest* request = [[NSMutableURLRequest alloc] initWithURL: nsUrl];
 
         if (shouldUsePostRequest)
             [request setHTTPMethod: @"POST"];
diff --git a/modules/juce_events/native/juce_android_Messaging.cpp b/modules/juce_events/native/juce_android_Messaging.cpp
index 7cee9b0730..f563d9904a 100644
--- a/modules/juce_events/native/juce_android_Messaging.cpp
+++ b/modules/juce_events/native/juce_android_Messaging.cpp
@@ -76,7 +76,7 @@ struct AndroidMessageQueue     : private Android::Runnable
     {
     }
 
-    ~AndroidMessageQueue()
+    ~AndroidMessageQueue() override
     {
         JUCE_ASSERT_MESSAGE_THREAD
         clearSingletonInstance();
@@ -156,14 +156,14 @@ void MessageManager::stopDispatchLoop()
             {
                 jmethodID quitMethod = env->GetMethodID (AndroidActivity, "finishAndRemoveTask", "()V");
 
-                if (quitMethod != 0)
+                if (quitMethod != nullptr)
                 {
                     env->CallVoidMethod (activity.get(), quitMethod);
                     return;
                 }
 
                 quitMethod = env->GetMethodID (AndroidActivity, "finish", "()V");
-                jassert (quitMethod != 0);
+                jassert (quitMethod != nullptr);
                 env->CallVoidMethod (activity.get(), quitMethod);
             }
             else
@@ -195,7 +195,7 @@ public:
         }
     }
 
-    ~JuceAppLifecycle()
+    ~JuceAppLifecycle() override
     {
         LocalRef<jobject> appContext (getAppContext());
 
diff --git a/modules/juce_graphics/image_formats/juce_JPEGLoader.cpp b/modules/juce_graphics/image_formats/juce_JPEGLoader.cpp
index 5c635717f7..413e519e34 100644
--- a/modules/juce_graphics/image_formats/juce_JPEGLoader.cpp
+++ b/modules/juce_graphics/image_formats/juce_JPEGLoader.cpp
@@ -43,6 +43,7 @@ namespace jpeglibNamespace
      #pragma clang diagnostic push
      #pragma clang diagnostic ignored "-Wconversion"
      #pragma clang diagnostic ignored "-Wdeprecated-register"
+     #pragma clang diagnostic ignored "-Wcast-align"
      #if __has_warning("-Wzero-as-null-pointer-constant")
       #pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"
      #endif
diff --git a/modules/juce_graphics/native/juce_android_Fonts.cpp b/modules/juce_graphics/native/juce_android_Fonts.cpp
index cf3e36146f..26445be2d7 100644
--- a/modules/juce_graphics/native/juce_android_Fonts.cpp
+++ b/modules/juce_graphics/native/juce_android_Fonts.cpp
@@ -374,7 +374,7 @@ public:
         {
             et = new EdgeTable (bounds);
 
-            jint* const maskDataElements = env->GetIntArrayElements ((jintArray) cachedRenderArray.get(), 0);
+            jint* const maskDataElements = env->GetIntArrayElements ((jintArray) cachedRenderArray.get(), nullptr);
             const jint* mask = maskDataElements;
 
             for (int y = bounds.getY(); y < bounds.getBottom(); ++y)
@@ -494,7 +494,7 @@ private:
         String key;
         {
             LocalRef<jobject> digest (env->CallStaticObjectMethod (JavaMessageDigest, JavaMessageDigest.getInstance, javaString("MD5").get()));
-            LocalRef<jbyteArray> bytes(env->NewByteArray(size));
+            LocalRef<jbyteArray> bytes(env->NewByteArray ((int) size));
 
             jboolean ignore;
             auto* jbytes = env->GetByteArrayElements(bytes.get(), &ignore);
diff --git a/modules/juce_gui_basics/filebrowser/juce_ContentSharer.cpp b/modules/juce_gui_basics/filebrowser/juce_ContentSharer.cpp
index 6f54fb35ea..ac2c443096 100644
--- a/modules/juce_gui_basics/filebrowser/juce_ContentSharer.cpp
+++ b/modules/juce_gui_basics/filebrowser/juce_ContentSharer.cpp
@@ -44,7 +44,7 @@ public:
         startThread();
     }
 
-    ~PrepareImagesThread()
+    ~PrepareImagesThread() override
     {
         signalThreadShouldExit();
         waitForThreadToExit (10000);
@@ -98,7 +98,7 @@ public:
         startThread();
     }
 
-    ~PrepareDataThread()
+    ~PrepareDataThread() override
     {
         signalThreadShouldExit();
         waitForThreadToExit (10000);
diff --git a/modules/juce_gui_basics/native/juce_MultiTouchMapper.h b/modules/juce_gui_basics/native/juce_MultiTouchMapper.h
index f72711bf54..af64d15ca3 100644
--- a/modules/juce_gui_basics/native/juce_MultiTouchMapper.h
+++ b/modules/juce_gui_basics/native/juce_MultiTouchMapper.h
@@ -35,7 +35,7 @@ public:
 
     int getIndexOfTouch (ComponentPeer* peer, IDType touchID)
     {
-        jassert (touchID != 0); // need to rethink this if IDs can be 0!
+        jassert (touchID != nullptr); // need to rethink this if IDs can be 0!
         TouchInfo info {touchID, peer};
 
         int touchIndex = currentTouches.indexOf (info);
@@ -64,7 +64,7 @@ public:
     bool areAnyTouchesActive() const noexcept
     {
         for (auto& t : currentTouches)
-            if (t.touchId != 0)
+            if (t.touchId != nullptr)
                 return true;
 
         return false;
@@ -74,14 +74,14 @@ public:
     {
         for (auto& t : currentTouches)
             if (t.owner == peer)
-                t.touchId = 0;
+                t.touchId = nullptr;
     }
 
 private:
     //==============================================================================
     struct TouchInfo
     {
-        TouchInfo() noexcept  : touchId (0), owner (nullptr) {}
+        TouchInfo() noexcept  : touchId (nullptr), owner (nullptr) {}
         TouchInfo (IDType idToUse, ComponentPeer* peer) noexcept  : touchId (idToUse), owner (peer) {}
 
         TouchInfo (const TouchInfo&) = default;
diff --git a/modules/juce_gui_basics/native/juce_android_ContentSharer.cpp b/modules/juce_gui_basics/native/juce_android_ContentSharer.cpp
index c8b58c7e1e..16ee696b56 100644
--- a/modules/juce_gui_basics/native/juce_android_ContentSharer.cpp
+++ b/modules/juce_gui_basics/native/juce_android_ContentSharer.cpp
@@ -135,7 +135,7 @@ public:
                                                                 resultColumns.get()))))
     {
         // the content provider must be created first
-        jassert (contentProvider.get() != 0);
+        jassert (contentProvider.get() != nullptr);
     }
 
     jobject getNativeCursor() { return cursor.get(); }
@@ -199,7 +199,7 @@ public:
                                                                       open | access | closeWrite | closeNoWrite))))
     {
         // the content provider must be created first
-        jassert (contentProvider.get() != 0);
+        jassert (contentProvider.get() != nullptr);
 
         env->CallVoidMethod (fileObserver, JuceContentProviderFileObserver.startWatching);
     }
@@ -284,7 +284,7 @@ public:
         startThread();
     }
 
-    ~AndroidContentSharerPrepareFilesThread()
+    ~AndroidContentSharerPrepareFilesThread() override
     {
         signalThreadShouldExit();
         waitForThreadToExit (10000);
@@ -307,7 +307,7 @@ private:
 
         ~StreamCloser()
         {
-            if (stream.get() != 0)
+            if (stream.get() != nullptr)
                 getEnv()->CallVoidMethod (stream, JavaCloseable.close);
         }
 
@@ -471,7 +471,7 @@ public:
     {
     }
 
-    ~ContentSharerNativeImpl()
+    ~ContentSharerNativeImpl() override
     {
         masterReference.clear();
     }
@@ -586,7 +586,7 @@ public:
             return cursor->getNativeCursor();
 
         auto values = LocalRef<jobjectArray> (env->NewObjectArray ((jsize) resultColumns.size(),
-                                                                   JavaObject, 0));
+                                                                   JavaObject, nullptr));
 
         for (int i = 0; i < resultColumns.size(); ++i)
         {
diff --git a/modules/juce_gui_basics/native/juce_android_FileChooser.cpp b/modules/juce_gui_basics/native/juce_android_FileChooser.cpp
index d95d4671b4..4ba5f50787 100644
--- a/modules/juce_gui_basics/native/juce_android_FileChooser.cpp
+++ b/modules/juce_gui_basics/native/juce_android_FileChooser.cpp
@@ -134,7 +134,7 @@ public:
             jassertfalse; // there can only be a single file chooser
     }
 
-    ~Native()
+    ~Native() override
     {
         masterReference.clear();
         currentFileChooser = nullptr;
diff --git a/modules/juce_gui_basics/native/juce_android_Windowing.cpp b/modules/juce_gui_basics/native/juce_android_Windowing.cpp
index 12c196f542..a881c4944a 100644
--- a/modules/juce_gui_basics/native/juce_android_Windowing.cpp
+++ b/modules/juce_gui_basics/native/juce_android_Windowing.cpp
@@ -318,7 +318,7 @@ public:
             handleFocusGain();
     }
 
-    ~AndroidComponentPeer()
+    ~AndroidComponentPeer() override
     {
         auto* env = getEnv();
 
@@ -466,7 +466,7 @@ public:
         LocalRef<jintArray> position (env->NewIntArray (2));
         env->CallVoidMethod (view.get(), AndroidView.getLocationOnScreen, position.get());
 
-        jint* const screenPosition = env->GetIntArrayElements (position.get(), 0);
+        jint* const screenPosition = env->GetIntArrayElements (position.get(), nullptr);
         Point<int> pos (screenPosition[0], screenPosition[1]);
         env->ReleaseIntArrayElements (position.get(), screenPosition, 0);
 
@@ -774,7 +774,7 @@ public:
             return;
         }
 
-        if (jint* dest = env->GetIntArrayElements ((jintArray) buffer.get(), 0))
+        if (jint* dest = env->GetIntArrayElements ((jintArray) buffer.get(), nullptr))
         {
             {
                 Image temp (new PreallocatedImage (clip.getWidth(), clip.getHeight(),
@@ -936,7 +936,7 @@ private:
                 zeromem (data_, static_cast<size_t> (width * height) * sizeof (jint));
         }
 
-        ~PreallocatedImage()
+        ~PreallocatedImage() override
         {
             if (hasAlpha)
             {
@@ -970,7 +970,7 @@ private:
 
         ImagePixelData::Ptr clone() override
         {
-            auto s = new PreallocatedImage (width, height, 0, hasAlpha);
+            auto s = new PreallocatedImage (width, height, nullptr, hasAlpha);
             s->allocatedData.malloc (sizeof (jint) * static_cast<size_t> (width * height));
             s->data = s->allocatedData;
             memcpy (s->data, data, sizeof (jint) * static_cast<size_t> (width * height));
@@ -1027,11 +1027,11 @@ Desktop::DisplayOrientation Desktop::getCurrentOrientation() const
 
     LocalRef<jobject> windowManager = LocalRef<jobject> (env->CallObjectMethod (getAppContext().get(), AndroidContext.getSystemService, windowServiceString.get()));
 
-    if (windowManager.get() != 0)
+    if (windowManager.get() != nullptr)
     {
         LocalRef<jobject> display = LocalRef<jobject> (env->CallObjectMethod (windowManager, AndroidWindowManager.getDefaultDisplay));
 
-        if (display.get() != 0)
+        if (display.get() != nullptr)
         {
             int rotation = env->CallIntMethod (display, AndroidDisplay.getRotation);
 
@@ -1414,7 +1414,7 @@ void Displays::findDisplays (float masterScale)
 
     jmethodID getRealMetricsMethod = env->GetMethodID (AndroidDisplay, "getRealMetrics", "(Landroid/util/DisplayMetrics;)V");
 
-    if (getRealMetricsMethod != 0)
+    if (getRealMetricsMethod != nullptr)
         env->CallVoidMethod (display.get(), getRealMetricsMethod, displayMetrics.get());
     else
         env->CallVoidMethod (display.get(), AndroidDisplay.getMetrics, displayMetrics.get());
diff --git a/modules/juce_gui_basics/native/juce_ios_ContentSharer.cpp b/modules/juce_gui_basics/native/juce_ios_ContentSharer.cpp
index 1111288356..da10b2ad35 100644
--- a/modules/juce_gui_basics/native/juce_ios_ContentSharer.cpp
+++ b/modules/juce_gui_basics/native/juce_ios_ContentSharer.cpp
@@ -38,7 +38,7 @@ public:
         popoverDelegate.reset ([cls.createInstance() init]);
     }
 
-    ~ContentSharerNativeImpl()
+    ~ContentSharerNativeImpl() override
     {
         exitModalState (0);
     }
diff --git a/modules/juce_gui_basics/native/juce_ios_FileChooser.mm b/modules/juce_gui_basics/native/juce_ios_FileChooser.mm
index cf5f613e0c..4cea7ea053 100644
--- a/modules/juce_gui_basics/native/juce_ios_FileChooser.mm
+++ b/modules/juce_gui_basics/native/juce_ios_FileChooser.mm
@@ -115,7 +115,7 @@ public:
         }
     }
 
-    ~Native()
+    ~Native() override
     {
         exitModalState (0);
     }
diff --git a/modules/juce_gui_basics/native/juce_ios_UIViewComponentPeer.mm b/modules/juce_gui_basics/native/juce_ios_UIViewComponentPeer.mm
index 0944ac34e6..34d0d6a10e 100644
--- a/modules/juce_gui_basics/native/juce_ios_UIViewComponentPeer.mm
+++ b/modules/juce_gui_basics/native/juce_ios_UIViewComponentPeer.mm
@@ -177,7 +177,7 @@ class UIViewComponentPeer  : public ComponentPeer,
 {
 public:
     UIViewComponentPeer (Component&, int windowStyleFlags, UIView* viewToAttachTo);
-    ~UIViewComponentPeer();
+    ~UIViewComponentPeer() override;
 
     //==============================================================================
     void* getNativeHandle() const override                  { return view; }
diff --git a/modules/juce_gui_extra/embedding/juce_AndroidViewComponent.h b/modules/juce_gui_extra/embedding/juce_AndroidViewComponent.h
index 8234437774..440b5a662f 100644
--- a/modules/juce_gui_extra/embedding/juce_AndroidViewComponent.h
+++ b/modules/juce_gui_extra/embedding/juce_AndroidViewComponent.h
@@ -50,7 +50,7 @@ public:
     AndroidViewComponent();
 
     /** Destructor. */
-    ~AndroidViewComponent();
+    ~AndroidViewComponent() override;
 
     /** Assigns a View to this peer.
 
diff --git a/modules/juce_gui_extra/embedding/juce_UIViewComponent.h b/modules/juce_gui_extra/embedding/juce_UIViewComponent.h
index ed04812f84..90c4bc6092 100644
--- a/modules/juce_gui_extra/embedding/juce_UIViewComponent.h
+++ b/modules/juce_gui_extra/embedding/juce_UIViewComponent.h
@@ -50,7 +50,7 @@ public:
     UIViewComponent();
 
     /** Destructor. */
-    ~UIViewComponent();
+    ~UIViewComponent() override;
 
     /** Assigns an UIView to this peer.
 
diff --git a/modules/juce_gui_extra/native/juce_AndroidViewComponent.cpp b/modules/juce_gui_extra/native/juce_AndroidViewComponent.cpp
index 82c283ff54..6f51d2abf7 100644
--- a/modules/juce_gui_extra/native/juce_AndroidViewComponent.cpp
+++ b/modules/juce_gui_extra/native/juce_AndroidViewComponent.cpp
@@ -39,7 +39,7 @@ public:
             componentPeerChanged();
     }
 
-    ~Pimpl()
+    ~Pimpl() override
     {
         removeFromParent();
     }
@@ -123,7 +123,7 @@ private:
         auto* env = getEnv();
         auto parentView = env->CallObjectMethod (view, AndroidView.getParent);
 
-        if (parentView != 0)
+        if (parentView != nullptr)
         {
             // Assuming a parent is always of ViewGroup type
             env->CallVoidMethod (parentView, AndroidViewGroup.removeView, view.get());
diff --git a/modules/juce_gui_extra/native/juce_android_PushNotifications.cpp b/modules/juce_gui_extra/native/juce_android_PushNotifications.cpp
index acbbf2e2ac..41bd3de2e0 100644
--- a/modules/juce_gui_extra/native/juce_android_PushNotifications.cpp
+++ b/modules/juce_gui_extra/native/juce_android_PushNotifications.cpp
@@ -280,7 +280,7 @@ struct PushNotifications::Pimpl
 
             auto notificationManager = getNotificationManager();
 
-            if (notificationManager.get() != 0)
+            if (notificationManager.get() != nullptr)
                 return env->CallBooleanMethod (notificationManager, NotificationManagerApi24.areNotificationsEnabled);
         }
 
@@ -297,7 +297,7 @@ struct PushNotifications::Pimpl
 
         auto notificationManager = getNotificationManager();
 
-        if (notificationManager.get() != 0)
+        if (notificationManager.get() != nullptr)
         {
             auto notification = juceNotificationToJavaNotification (n);
 
@@ -317,10 +317,9 @@ struct PushNotifications::Pimpl
             Array<PushNotifications::Notification> notifications;
 
             auto notificationManager = getNotificationManager();
+            jassert (notificationManager != nullptr);
 
-            jassert (notificationManager.get() != 0);
-
-            if (notificationManager.get() != 0)
+            if (notificationManager.get() != nullptr)
             {
                 auto statusBarNotifications = LocalRef<jobjectArray> ((jobjectArray)env->CallObjectMethod (notificationManager,
                                                                                                            NotificationManagerApi23.getActiveNotifications));
@@ -389,7 +388,7 @@ struct PushNotifications::Pimpl
             auto remoteInputResult = LocalRef<jobject> (env->CallStaticObjectMethod (RemoteInput, RemoteInput.getResultsFromIntent, intent.get()));
             String responseString;
 
-            if (remoteInputResult.get() != 0)
+            if (remoteInputResult.get() == nullptr)
             {
                 auto charSequence      = LocalRef<jobject> (env->CallObjectMethod (remoteInputResult, AndroidBundle.getCharSequence, resultKeyString.get()));
                 auto responseStringRef = LocalRef<jstring> ((jstring) env->CallObjectMethod (charSequence, JavaCharSequence.toString));
@@ -416,7 +415,7 @@ struct PushNotifications::Pimpl
 
         auto notificationManager = getNotificationManager();
 
-        if (notificationManager.get() != 0)
+        if (notificationManager.get() != nullptr)
             env->CallVoidMethod (notificationManager.get(), NotificationManagerBase.cancelAll);
     }
 
@@ -426,7 +425,7 @@ struct PushNotifications::Pimpl
 
         auto notificationManager = getNotificationManager();
 
-        if (notificationManager.get() != 0)
+        if (notificationManager.get() != nullptr)
         {
             auto tag = javaString (identifier);
             const int id = 0;
@@ -635,12 +634,12 @@ struct PushNotifications::Pimpl
         LocalRef<jobject> context (getMainActivity());
 
         jclass builderClass = env->FindClass ("android/app/Notification$Builder");
-        jassert (builderClass != 0);
+        jassert (builderClass != nullptr);
 
-        if (builderClass == 0)
-            return LocalRef<jobject> (0);
+        if (builderClass == nullptr)
+            return LocalRef<jobject> (nullptr);
 
-        jmethodID builderConstructor = 0;
+        jmethodID builderConstructor = nullptr;
 
         const bool apiAtLeast26 = (getAndroidSDKVersion() >= 26);
 
@@ -649,10 +648,10 @@ struct PushNotifications::Pimpl
         else
             builderConstructor = env->GetMethodID (builderClass, "<init>", "(Landroid/content/Context;)V");
 
-        jassert (builderConstructor != 0);
+        jassert (builderConstructor != nullptr);
 
-        if (builderConstructor == 0)
-            return LocalRef<jobject> (0);
+        if (builderConstructor == nullptr)
+            return LocalRef<jobject> (nullptr);
 
         if (apiAtLeast26)
             return LocalRef<jobject> (env->NewObject (builderClass, builderConstructor,
@@ -754,7 +753,7 @@ struct PushNotifications::Pimpl
         {
             auto array = LocalRef<jlongArray> (env->NewLongArray (size));
 
-            jlong* elements = env->GetLongArrayElements (array, 0);
+            jlong* elements = env->GetLongArrayElements (array, nullptr);
 
             for (int i = 0; i < size; ++i)
                 elements[i] = (jlong) n.vibrationPattern[i];
@@ -808,7 +807,7 @@ struct PushNotifications::Pimpl
             {
                 auto array = LocalRef<jlongArray> (env->NewLongArray (size));
 
-                jlong* elements = env->GetLongArrayElements (array, 0);
+                jlong* elements = env->GetLongArrayElements (array, nullptr);
 
                 for (int i = 0; i < size; ++i)
                     elements[i] = (jlong) n.vibrationPattern[i];
@@ -993,7 +992,7 @@ struct PushNotifications::Pimpl
 
                         const int size = action.allowedResponses.size();
 
-                        auto array = LocalRef<jobjectArray> (env->NewObjectArray (size, env->FindClass ("java/lang/String"), 0));
+                        auto array = LocalRef<jobjectArray> (env->NewObjectArray (size, env->FindClass ("java/lang/String"), nullptr));
 
                         for (int i = 0; i < size; ++i)
                         {
@@ -1123,7 +1122,7 @@ struct PushNotifications::Pimpl
 
         PushNotifications::Notification n;
 
-        if (bundle.get() != 0)
+        if (bundle.get() != nullptr)
         {
             n.identifier  = getStringFromBundle (env, "identifier", bundle);
             n.title       = getStringFromBundle (env, "title", bundle);
@@ -1239,7 +1238,7 @@ struct PushNotifications::Pimpl
 
             const int size = env->GetArrayLength (array.get());
 
-            jlong* elements = env->GetLongArrayElements (array.get(), 0);
+            jlong* elements = env->GetLongArrayElements (array.get(), nullptr);
 
             Array<int> resultArray;
 
@@ -1280,7 +1279,7 @@ struct PushNotifications::Pimpl
 
     static var bundleToVar (const LocalRef<jobject>& bundle)
     {
-        if (bundle.get() != 0)
+        if (bundle.get() == nullptr)
         {
             auto* env = getEnv();
 
@@ -1400,7 +1399,7 @@ struct PushNotifications::Pimpl
             propertiesDynamicObject->setProperty ("titleLocalizationKey",  juceString (titleLocalizationKey.get()));
             propertiesDynamicObject->setProperty ("bodyLocalizationArgs",  javaStringArrayToJuce (bodyLocalizationArgs));
             propertiesDynamicObject->setProperty ("titleLocalizationArgs", javaStringArrayToJuce (titleLocalizationArgs));
-            propertiesDynamicObject->setProperty ("link",                  link.get() != 0 ? juceString ((jstring) env->CallObjectMethod (link, AndroidUri.toString)) : String());
+            propertiesDynamicObject->setProperty ("link",                  link.get() == nullptr ? juceString ((jstring) env->CallObjectMethod (link, AndroidUri.toString)) : String());
         }
 
         n.properties = var (propertiesDynamicObject.get());
@@ -1418,9 +1417,9 @@ struct PushNotifications::Pimpl
 
         auto notificationManager = getNotificationManager();
 
-        jassert (notificationManager.get() != 0);
+        jassert (notificationManager.get() != nullptr);
 
-        if (notificationManager.get() == 0)
+        if (notificationManager.get() == nullptr)
             return;
 
         for (const auto& g : groups)
@@ -1463,7 +1462,7 @@ struct PushNotifications::Pimpl
             if (size > 0)
             {
                 auto array = LocalRef<jlongArray> (env->NewLongArray (size));
-                jlong* elements = env->GetLongArrayElements (array, 0);
+                jlong* elements = env->GetLongArrayElements (array, nullptr);
 
                 for (int i = 0; i < size; ++i)
                     elements[i] = (jlong) c.vibrationPattern[i];
@@ -1527,7 +1526,7 @@ struct PushNotifications::Pimpl
 
         auto categories = LocalRef<jobject> (env->CallObjectMethod (intent, AndroidIntent.getCategories));
 
-        int categoriesNum = categories != 0
+        int categoriesNum = categories != nullptr
                           ? env->CallIntMethod (categories, JavaSet.size)
                           : 0;
 
@@ -1542,7 +1541,7 @@ struct PushNotifications::Pimpl
 
         auto extras = LocalRef<jobject> (env->CallObjectMethod (intent, AndroidIntent.getExtras));
 
-        if (extras == 0)
+        if (extras == nullptr)
             return false;
 
         return env->CallBooleanMethod (extras, AndroidBundle.containsKey, javaString ("google.sent_time").get())
diff --git a/modules/juce_gui_extra/native/juce_android_WebBrowserComponent.cpp b/modules/juce_gui_extra/native/juce_android_WebBrowserComponent.cpp
index ed1a125ca5..4661ff368e 100644
--- a/modules/juce_gui_extra/native/juce_android_WebBrowserComponent.cpp
+++ b/modules/juce_gui_extra/native/juce_android_WebBrowserComponent.cpp
@@ -424,7 +424,7 @@ private:
             startThread();
         }
 
-        ~ConnectionThread()
+        ~ConnectionThread() override
         {
             webInputStream->cancel();
             signalThreadShouldExit();
@@ -559,11 +559,11 @@ private:
 
         LocalRef<jclass> responseClass (env->FindClass ("android/webkit/WebResourceResponse"));
 
-        if (responseClass != 0)
+        if (responseClass != nullptr)
         {
             jmethodID method = env->GetMethodID (responseClass, "getReasonPhrase", "()Ljava/lang/String;");
 
-            if (method != 0)
+            if (method != nullptr)
             {
                 auto errorString = LocalRef<jstring> ((jstring) env->CallObjectMethod (errorResponse, method));
 
@@ -671,7 +671,7 @@ void WebBrowserComponent::checkWindowAssociation()
             // page to avoid this, (and send it back when it's made visible again).
 
             blankPageShown = true;
-            browser->goToURL ("about:blank", 0, 0);
+            browser->goToURL ("about:blank", nullptr, nullptr);
         }
     }
 }
@@ -711,7 +711,7 @@ void WebBrowserComponent::clearCookies()
     auto cookieManager = LocalRef<jobject> (env->CallStaticObjectMethod (AndroidCookieManager,
                                                                          AndroidCookieManager.getInstance));
 
-    jmethodID clearCookiesMethod = 0;
+    jmethodID clearCookiesMethod = nullptr;
 
     if (getAndroidSDKVersion() >= 21)
     {
diff --git a/modules/juce_gui_extra/native/juce_ios_UIViewComponent.mm b/modules/juce_gui_extra/native/juce_ios_UIViewComponent.mm
index 2aa4747480..7053ed6a23 100644
--- a/modules/juce_gui_extra/native/juce_ios_UIViewComponent.mm
+++ b/modules/juce_gui_extra/native/juce_ios_UIViewComponent.mm
@@ -41,7 +41,7 @@ public:
             componentPeerChanged();
     }
 
-    ~Pimpl()
+    ~Pimpl() override
     {
         [view removeFromSuperview];
         [view release];
diff --git a/modules/juce_opengl/native/juce_OpenGL_android.h b/modules/juce_opengl/native/juce_OpenGL_android.h
index d0c4d5f809..9265fa01ff 100644
--- a/modules/juce_opengl/native/juce_OpenGL_android.h
+++ b/modules/juce_opengl/native/juce_OpenGL_android.h
@@ -118,7 +118,7 @@ public:
         hasInitialised = true;
     }
 
-    ~NativeContext()
+    ~NativeContext() override
     {
         auto env = getEnv();
 
@@ -165,7 +165,7 @@ public:
         }
 
         // create the surface
-        surface = eglCreateWindowSurface (display, config, window, 0);
+        surface = eglCreateWindowSurface (display, config, window, nullptr);
         jassert (surface != EGL_NO_SURFACE);
 
         ANativeWindow_release (window);
@@ -317,7 +317,7 @@ private:
             return false;
         }
 
-        if (! eglInitialize (display, 0, 0))
+        if (! eglInitialize (display, nullptr, nullptr))
         {
             jassertfalse;
             return false;
diff --git a/modules/juce_opengl/opengl/juce_OpenGLContext.cpp b/modules/juce_opengl/opengl/juce_OpenGLContext.cpp
index e59b1f9b7b..d3acf0ecc6 100644
--- a/modules/juce_opengl/opengl/juce_OpenGLContext.cpp
+++ b/modules/juce_opengl/opengl/juce_OpenGLContext.cpp
@@ -40,8 +40,8 @@ extern Array<AppInactivityCallback*> appBecomingInactiveCallbacks;
 // this prevents them from happening (which some messy locking behaviour)
 struct iOSBackgroundProcessCheck  : public AppInactivityCallback
 {
-    iOSBackgroundProcessCheck()     { isBackgroundProcess(); appBecomingInactiveCallbacks.add (this); }
-    ~iOSBackgroundProcessCheck()    { appBecomingInactiveCallbacks.removeAllInstancesOf (this); }
+    iOSBackgroundProcessCheck()              { isBackgroundProcess(); appBecomingInactiveCallbacks.add (this); }
+    ~iOSBackgroundProcessCheck() override    { appBecomingInactiveCallbacks.removeAllInstancesOf (this); }
 
     bool isBackgroundProcess()
     {
diff --git a/modules/juce_video/native/juce_android_CameraDevice.h b/modules/juce_video/native/juce_android_CameraDevice.h
index 783eb178e9..30aa1ab924 100644
--- a/modules/juce_video/native/juce_android_CameraDevice.h
+++ b/modules/juce_video/native/juce_android_CameraDevice.h
@@ -508,7 +508,7 @@ struct CameraDevice::Pimpl
         startBackgroundThread();
     }
 
-    ~Pimpl()
+    ~Pimpl() override
     {
         auto* env = getEnv();
 
@@ -764,18 +764,18 @@ private:
 
         auto* env = getEnv();
 
-        #define PRINT_ELEMENTS(elem_type, array_type, fun_name_middle)                                        \
-        {                                                                                                     \
-            elem_type* elements = env->Get##fun_name_middle##ArrayElements ((array_type) keyValue.get(), 0);  \
-            int size = env->GetArrayLength ((array_type) keyValue.get());                                     \
-                                                                                                              \
-            for (int i = 0; i < size - 1; ++i)                                                                \
-                result << String (elements[i]) << " ";                                                        \
-                                                                                                              \
-            if (size > 0)                                                                                     \
-                result << String (elements[size - 1]);                                                        \
-                                                                                                              \
-            env->Release##fun_name_middle##ArrayElements ((array_type) keyValue.get(), elements, 0);          \
+        #define PRINT_ELEMENTS(elem_type, array_type, fun_name_middle)                                              \
+        {                                                                                                           \
+            elem_type* elements = env->Get##fun_name_middle##ArrayElements ((array_type) keyValue.get(), nullptr);  \
+            int size = env->GetArrayLength ((array_type) keyValue.get());                                           \
+                                                                                                                    \
+            for (int i = 0; i < size - 1; ++i)                                                                      \
+                result << String (elements[i]) << " ";                                                              \
+                                                                                                                    \
+            if (size > 0)                                                                                           \
+                result << String (elements[size - 1]);                                                              \
+                                                                                                                    \
+            env->Release##fun_name_middle##ArrayElements ((array_type) keyValue.get(), elements, 0);                \
         }
 
         if (keyValueString.startsWith ("[I"))
@@ -996,7 +996,7 @@ private:
                                                           "android/view/TextureView$SurfaceTextureListener").get());
         }
 
-        ~PreviewDisplay()
+        ~PreviewDisplay() override
         {
             getEnv()->CallVoidMethod (textureView, AndroidTextureView.setSurfaceTextureListener, nullptr);
         }
@@ -1144,7 +1144,7 @@ private:
                                       handlerToUse.get());
         }
 
-        ~ImageReader()
+        ~ImageReader() override
         {
             getEnv()->CallVoidMethod (imageReader, AndroidImageReader.close);
         }
@@ -1405,7 +1405,7 @@ private:
             getEnv()->CallVoidMethod (mediaRecorder, AndroidMediaRecorder.prepare);
         }
 
-        ~MediaRecorder()
+        ~MediaRecorder() override
         {
             getEnv()->CallVoidMethod (mediaRecorder, AndroidMediaRecorder.release);
         }
@@ -2494,7 +2494,7 @@ private:
     //==============================================================================
     struct CaptureSessionModeBase
     {
-        virtual ~CaptureSessionModeBase() { }
+        virtual ~CaptureSessionModeBase() = default;
 
         virtual bool isVideoRecordSession() const = 0;
 
@@ -2507,7 +2507,7 @@ private:
                                   private PreviewDisplay::Listener,
                                   private ScopedCameraDevice::CaptureSession::ConfiguredCallback
     {
-        ~CaptureSessionMode()
+        ~CaptureSessionMode() override
         {
             captureSession.reset();
 
@@ -2789,7 +2789,7 @@ private:
             setEnabled (true);
         }
 
-        ~DeviceOrientationChangeListener()
+        ~DeviceOrientationChangeListener() override
         {
             setEnabled (false);
         }
@@ -2985,7 +2985,7 @@ private:
     {
         auto* env = getEnv();
 
-        auto* jArrayElems = env->GetIntArrayElements (jArray, 0);
+        auto* jArrayElems = env->GetIntArrayElements (jArray, nullptr);
         auto numElems = env->GetArrayLength (jArray);
 
         Array<int> juceArray;
diff --git a/modules/juce_video/native/juce_android_Video.h b/modules/juce_video/native/juce_android_Video.h
index b416d064e8..7c7beeadcc 100644
--- a/modules/juce_video/native/juce_android_Video.h
+++ b/modules/juce_video/native/juce_android_Video.h
@@ -375,7 +375,7 @@ struct VideoComponent::Pimpl
         }
     }
 
-    ~Pimpl()
+    ~Pimpl() override
     {
         auto* env = getEnv();
 
@@ -502,7 +502,7 @@ private:
             env->CallVoidMethod (nativeMediaSession, AndroidMediaSession.setCallback, mediaSessionCallback.get());
         }
 
-        ~MediaSession()
+        ~MediaSession() override
         {
             auto* env = getEnv();
 
@@ -1405,7 +1405,7 @@ private:
 
             auto playPos = player.getPlayPosition();
             auto durationMs = player.getVideoDuration();
-            int playPosPercent = 100 * playPos / static_cast<double> (durationMs);
+            auto playPosPercent = (int) (100.0 * playPos / static_cast<double> (durationMs));
 
             // NB: assuming the playback will start roughly when there is 5% of content loaded...
             return ! bufferedRegions.containsRange (Range<int> (playPosPercent, jmin (101, playPosPercent + 5)));
@@ -1456,7 +1456,7 @@ private:
 
             auto playPos = player.getPlayPosition();
             auto durationMs = player.getVideoDuration();
-            int playPosPercent = 100 * playPos / static_cast<double> (durationMs);
+            auto playPosPercent = (int) (100.0 * playPos / static_cast<double> (durationMs));
 
             bufferedRegions.addRange (Range<int> (playPosPercent, progress + 1));
 
diff --git a/modules/juce_video/native/juce_ios_CameraDevice.h b/modules/juce_video/native/juce_ios_CameraDevice.h
index 9147735117..edefe326c1 100644
--- a/modules/juce_video/native/juce_ios_CameraDevice.h
+++ b/modules/juce_video/native/juce_ios_CameraDevice.h
@@ -304,7 +304,7 @@ private:
 
     static String cmTimeToString (CMTime time)
     {
-        CFStringRef timeDesc = CMTimeCopyDescription (NULL, time);
+        CFStringRef timeDesc = CMTimeCopyDescription (nullptr, time);
         String result = String::fromCFString (timeDesc);
 
         CFRelease (timeDesc);
@@ -984,7 +984,7 @@ private:
         class VideoRecorder
         {
         public:
-            VideoRecorder (CaptureSession& captureSession)
+            VideoRecorder (CaptureSession& session)
                 : movieFileOutput ([AVCaptureMovieFileOutput new]),
                   delegate (nullptr)
             {
@@ -992,7 +992,7 @@ private:
                 delegate.reset ([cls.createInstance() init]);
                 FileOutputRecordingDelegateClass::setOwner (delegate.get(), this);
 
-                captureSession.addOutputIfPossible (movieFileOutput);
+                session.addOutputIfPossible (movieFileOutput);
             }
 
             ~VideoRecorder()