c++删除指针然后访问它指向的值

Question

我刚刚在 C++ 类中学习了指针和删除指针。我自己试过这段代码

# include<iostream>

using namespace std;

int main(){
    int num = 10;
    int *p = new int;

    p = &num;
    cout << *p << endl;
    delete p;
    cout << num << endl;
    return 0;
}

删除指针后p , 我无法打印 num 的值.但是如果我删除 p在程序的最后，cout << num << endl;会给我 10。有人知道我跑到哪里了吗？

Answer 1

你先泄露了一个指针

int *p = new int;
p = #  // You just leaked the above int

然后非法删除了一些你没有new

的东西

delete p;  // p points to num, which you did not new