C++ const的应用

#include <iostream>
#include <string>
#include <windows.h>
using namespace std;
int main() {
    int girl = 19;
    int boy = 21;

    int const* p1 = &girl;  //不能修改指向变量的值,其中int const * p1 = &girl等同于const int * p1 = &girl;
    //*p1 = 22;  //这些有注释的都是不能被正常运行的
    girl = 26;
    //p1 = 28;
    p1 = &boy;
    printf("p1所指向的变量的值是：%d\n", *p1);
    printf("girl的年龄是：%d\n", girl);
    printf("boy的年龄是：%d\n\n", boy);

    int* const p2 = &girl;  //不允许指向别的地址
    *p2 = 27;
    printf("p2所指向的变量的值是：%d\n", *p2);
    girl = 33;
    //p2 = &boy;
    printf("girl的年龄是：%d\n\n", girl);

    const int* const p3 = &girl;  //不允许指向别的地址，也不能修改指向变量的值
    //*p3 = 27;
    girl = 35;
    //p3 = &boy;         
    printf("p2所指向的变量的值是：%d\n", *p3);
    printf("girl的年龄是：%d\n", girl);

    system("pause");
    return 0;
}   //总结：const离谁越近，谁就不能被修改