什么是C ++的“删除”运营商实际上做什么？ [英] What does C++'s "delete" operator actually do?

问题描述

我认为它释放了先前分配的内存，但我可能错了：

I thought that it freed previously allocated memory, but I may be wrong:

class Person {
    public:
        Person(string, int, double);
        ~Person();
        int age;
        string name;
        double weight;
};

int main() {
    Person* p = new Person("Jane", 20, 130);
    cout << p->age; // prints 20
    delete p;
    cout << p->age; // prints 20 again...
}

推荐答案

这是未定义的行为。

释放/删除内存不意味着它将被清零，它只意味着该内存可以再次用于未来的分配。

Freeing/Deleting the memory does not mean it will be zeroed, it only means that that memory can be used again for future allocations. You should never try to use freed/deleted memory.

使用 delete 大于 free ，如果不适当地转换，它也会调用你的变量的析构函数。

With the delete case over free, it will also call the destructor of your variable if not casted improperly.

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