Editing Pointer (computer programming) (section)

===Pass-by-address using pointers===
Pointers can be used to pass variables by their address, allowing their value to be changed. For example, consider the following [[C (programming language)|C]] code:

<syntaxhighlight lang="C">
/* a copy of the int n can be changed within the function without affecting the calling code */
void passByValue(int n) {
    n = 12;
}

/* a pointer m is passed instead. No copy of the value pointed to by m is created */
void passByAddress(int *m) {
    *m = 14;
}

int main(void) {
    int x = 3;

    /* pass a copy of x's value as the argument */
    passByValue(x);
    // the value was changed inside the function, but x is still 3 from here on

    /* pass x's address as the argument */
    passByAddress(&x);
    // x was actually changed by the function and is now equal to 14 here

    return 0;
}
</syntaxhighlight>