What happens to a parameter passed by value that is modified locally?

Question

I am well aware that modifying a function\'s argument that is passed by value is ineffective outside of the C/C++ function, but compilers allow it - but what happens? Is a loca

Answer 1

A value parameter of a function is effectively a local variable of the function, except that it is initialised in the function call. So these:

 void f( int n ) {
      n++;
   }

and:

 void g() {
      int n = 0;
      n++;
   }

are effectively the same, if the call to f() was made as f(0). In both cases, the variable will be discarded on function exit.