Sams Teach Yourself Cocoa Touch™ Programming in 24 Hours

Appendix D. Advanced Topics

Testing String Mutability with Exceptions

We can test a string’s mutability as follows. Again don’t use this for production code.

(Casting string to id removes a static type check warning.)

Uncaught Exceptions

Any exceptions you do not catch invoke the default exception handler. You can set your own default exception handler with NSSetUncaughtExceptionHandler which takes as argument a pointer to a function handler. (Recall that in C, the & operator returns the address of its argument. Thus &myHandler is a pointer to the myHandler function). You can obtain the system’s handler with NSGetUncaughtExceptionHandler.