objcCurrency string from a number (double)Converting a decimal number to a currency string is simple with NSNumberFormatter.
ios, ios-8, objcfileExistsAtPath always returns NO (false)Generating the path dynamically with NSSearchPathForDirectoriesInDomains.
ios, objcNSURL URLWithString vs fileURLWithPathA frequent mistake when playing a local video using [AVAudioPlayer initWithContentsOfURL:url] is to use URLWithString instead of fileURLWithPath.
xcode, objc, swift, auto-layoutDebugging view constraints with Xcode 7A small button named 'Debug view hierarchy', displays current view hierarchy in 3D.
