c - Changing the value of something in a function

Question

This is a test case for something larger, which is why it is written the way is. How could I make this bit of code so that a's value would keep incrementing? In my project I call a function that parses a line from a file. I need to set values of a struct to certain values that were set in the function call (the parameters of the function were initialized in the main function, like the code below).

int increment(int a)
{
    a++;
    return 0;
}
int main()
{
    int a =0;
    int b =0;
    while( b<5){
        increment(a);
        b++;
        cout << "a is: " << a << ". And b is: " << b << "
";
    }
    system("PAUSE");
}

Thanks.

Answer 1

Pass its address to increment

void increment(int *a){
  (*a)++;  
}
increment(&a);
//Using the address of operator pass in the address of a as argument