Cy-4AH questions

Cy-4AH answers

• compiling a #include <cstdlib> in Xcode - error during compilation: file not found
• Using valueForKeyPath on an NSArray, how to count a BOOL property if property is set to YES
• "if (@available(iOS 13.0, *))" doesn't compile in Xcode 10.3
• Why does passing an unsigned int to performSelector lose bits?
• Wait for async task to finish completion block before returning in app delegate
• iPhone getting crazy hot and app lagging and crashing with Admob interstitial ads
• Can a category access instance variables defined in the class it extends?
• Adding C file causes pch error
• How to add image UIImage with indent in UITextField in iOS 7?
• How to delete Keychain data when app is uninstalled? [duplicate]