Tutorial by Examples

When your app crashes, Xcode will enter the debugger and show you more information about the crash: The most important parts are: The red arrow The red arrow displays which line of code crashed & why it crashed. The debugger console Many crashes log more information to the debugger consol...

A SIGABRT or an EXC_BAD_INSTRUCTION usually means the app crashed itself intentionally because some check failed. These should log a message to the debugger console with more information; check there for more information. Many SIGABRTs are caused by uncaught Objective-C exceptions. There are a lo...

EXC_BAD_ACCESS means the process tried to access memory in an invalid way, like dereferencing a NULL pointer or writing to read-only memory. This is the hardest kind of crash to debug, because it usually does not have an error message, and some crashes can be very difficult to reproduce and/or occu...