C基础知识(4)：指针--p=&a和*p=a的区别详解

对于*p，[p = &a]和[*p = a]的区别详解

(1) p=&a就是用a的地址对p赋值，&p不改变，变的是p

(2) *p=a就是把p所指向的那一内存空间的值赋值为a，&p和p都不改变，变的是p所指向的那一内存空间的值

#include <stdio.h>

// 对于*p，[p = &a]和[*p = a]的区别详解
int main() {
    int init = 0;
    // p=&a就是用a的地址对p赋值，&p不改变，变的是p
    int a = 10;
    int *p = &init;
    printf("[p] = %p; [*p] = %d; [&p] = %p;
", p, *p, &p); //[p] = 0x7ffe12baad9c; [*p] = 0;  [&p] = 0x7ffe12baad90;
    p = &a;
    printf("[p] = %p; [*p] = %d; [&p] = %p;
", p, *p, &p); //[p] = 0x7ffe12baad98; [*p] = 10; [&p] = 0x7ffe12baad90;
    printf("[init] = %d;
", &init, init); //0

    // *q=b就是把q所指向的那一内存空间的值赋值为b，&q q都不改变，变的是q所指向的那一内存空间的值，即init的值
    int b = 20;
    int *q = &init;
    printf("[&b] = %p; [q] = %p; [*q] = %d; [&q] = %p;
", &b, q, *q, &q); //[q] = 0x7ffe12baad9c; [*q] = 0;  [&q] = 0x7ffe12baad80;
    *q = b;
    printf("[&b] = %p; [q] = %p; [*q] = %d; [&q] = %p;
", &b, q, *q, &q); //[q] = 0x7ffe12baad9c; [*q] = 20; [&q] = 0x7ffe12baad80;
    printf("[&init] = %p; [init] = %d;
", &init, init); //20
    return 0;
}

代码分析：