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Pointers (cont)

For a function to be able to change the "actual" value of a variable, we need to pass a pointer as a parameter.
  • swap() – the wrong way 

    void swap(int a, int b) {
    int temp;
    temp = a; a = b; b = temp;   // only the local "copies" of a and b will swap
}

void test(void) {
    int a = 5, b = 7;
    swap(a, b);
    printf("a = %d, b = %d\n", a, b);  // a and b will have their original value
}