What is the value of 'x' for each scenario?

Question

I have the following C-like program, and I'm trying to figure out the final value of array x for when:

• Argument x is passed by value.
• Argument x is passed by reference.
• Argument x is passed by value-result.

CODE:

void swap(int[] list, int i, int j)
{
    int temp = list[i];
    list[i] = list[j];
    list[j] = temp;
}

void main() 
{
    int x[3] = {5, 2, 4};
    swap(x, 1, 2);
}

If I'm following correctly, for pass by value, in the call we have...

swap(x, 1, 2)
{
    temp = x[1] // temp now equals 2
    x[1] = x[2] // x[1] now equals 4
    x[2] = temp // x[2] now equals 2
}

...so then we have the following, correct?

x[3] == {5, 4, 2}

EDIT:

I tried compiling on ideone.com and received:

prog.c:1:17: error: expected ‘;’, ‘,’ or ‘)’ before ‘list’
 void swap(int[] list, int i, int j)
                 ^
prog.c:8:6: warning: return type of ‘main’ is not ‘int’ [-Wmain]
 void main() 
      ^
prog.c: In function ‘main’:
prog.c:11:5: warning: implicit declaration of function ‘swap’ [-Wimplicit-function-declaration]
     swap(x, 1, 2);
     ^

Answer 1

Actually, when you call

swap(x, 1, 2);

you are using call-by reference, since you are passing the argument x, which is a pointer to the first element of the array x. So this swap technique will work and you will get what you are expecting, that the elements will now be in the order {5,4,2}