Question

Given the following code, will ixAdd do what you’d expect, i. e. return the value of ix before the increment, but increment the class member before leaving the function?

class myCounter {     private int _ix = 1;      public int ixAdd()     {         return _ix++;     } } 

I wasn’t quite sure if the usual rules for post / pre increment would also apply in return statements, when the program leaves the stack frame (or whatever it is in Java) of the function.

Answer 1

The key part is that a post increment/decrement happens immediately after the expression is evaluated. Not only does it happen before the return occurs – it happens before any later expressions are evaluated. For instance, suppose you wrote:

class myCounter {     private int _ix = 1;      public int ixAdd()     {         return _ix++ + giveMeZero();     }      public int giveMeZero()     {         System.out.println(_ix);         return 0;     } } 

That would print out the incremented result as well, because the increment happens before giveMeZero() is called.