DoublePointer (**)

双重指针

#include<stdio.h>

int main(viod)
{
    int a = 1;
    int b = 2;
    int * p = &a;
    int * p1 = p;
    int * p2 = &b;

    printf("a`s adress = %p", p);
    printf("\n p1`s value = %p", p1);
    alterPointer(p, p2);
    printf("\n%p---%p", p, p2);
    printf("\na = %d", (*p));
    printf("\nb = %d", (*p2));
    alterPointerP(&p, p2);
    //alterPointerp(p, p2);
    printf("\n%p---%p", p, p2);
    printf("\n%d", (*p));
}

void alterPointer(int * pointer, int * pointer1)
{
    (* pointer) = 3;
}

void alterPointerP(int ** doublePointer, int * pointer)
{
    (*doublePointer) = pointer;
}