Câu hỏi phỏng vấn Objective-C
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What happens when you invok...

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Invoking a Method on a Nil Pointer in Objective-C

In Objective-C, when you invoke a method on a nil pointer, the runtime will simply ignore the message and return nil. This behavior is known as "messaging nil" and is a fundamental part of the Objective-C runtime.

Here's what happens when you invoke a method on a nil pointer:

  1. The method is not executed: The code inside the method will not be executed, and the method will return immediately.

  2. No crash or exception: Messaging nil will not cause a crash or raise an exception. The runtime simply ignores the message and continues execution.

  3. Return value is nil: If the method has a return value, it will return nil (or 0 for primitive types like int or float).

Here's an example:

objc Copy
NSString *myString = nil;
NSString *result ...
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