NSParameterAssert

NSParameterAssert

 

Validates the specified parameter.

NSParameterAssert(condition)

 

Discussion

Assertions evaluate a condition and, if the condition evaluates to false, call the assertion handler for the current thread, passing it a format string and a variable number of arguments. Each thread has its own assertion handler, which is an object of class NSAssertionHandler. When invoked, an assertion handler prints an error message that includes method and class names (or the function name). It then raises an NSInternalInconsistencyException exception.

This macro validates a parameter for an Objective-C method. Simply provide the parameter as the condition argument. The macro evaluates the parameter and, if it is false, it logs an error message that includes the parameter and then raises an exception.

Assertions are disabled if the preprocessor macro NS_BLOCK_ASSERTIONS is defined. All assertion macros return void.

Availability

• Available in Mac OS X v10.0 and later.