[Solved] in the ViewController.m, what’s the difference between self.username with _username [duplicate]

The self.username will call the setter of the username that’s why the breakpoint jumps to the synthesize statement. When you a _variable, then the property can be accessed using the _variable. And in your case: self.username stores the value to ivar _username and _username = @”admin”; is also stores the value to _username ivar. Means … Read more