Xcode debugger sometimes won't step into a method

Question

Sometimes when I press the "step into" button in the Xcode debugger, it instead steps over the method call.

This happens even though the method is a method I wrote, and the source code is in the same project.

Can anyone explain how to prevent this?

Answer 1

This may also happen when the method is being called on a nil object.

From Apple's developer docs:

A nil value is the safest way to initialize an object pointer if you don’t have another value to use, because it’s perfectly acceptable in Objective-C to send a message to nil. If you do send a message to nil, obviously nothing happens.

This is not necessarily so obvious if you've used pretty much any other language, because they largely don't include this "feature."