Pass by reference...

 #include <stdio.h>

void display( int *);

int main()

{ int num = 10;

    printf("num = %d\n", num);

    printf("memory location of num variable is %u\n", &num);

display(&num);

printf("now i am completed pass by refrence too\n");

    return 0;

}

void display(int *pointer){

    

;

    printf(" value at pointer variable is  %d\n", *pointer);

    printf("memory address of pointer is %u\n", &pointer);

    

     *pointer = 20;

    printf("memory address of pointer is %u\n", *pointer);

}