析构函数在c ++中调用两次，但构造函数只调用一次 [英] Destructor getting called twice in c++ but the constructor only once

问题描述

我的代码是

    class CTemp{
public:
    CTemp(){
        printf("\nIn cons");
    }
    ~CTemp(){
        printf("\nIn dest");
    }
};

void Dowork(CTemp obj)
{
    printf("\nDo work");
}

int main()
{
    CTemp * obj = new CTemp();
    Dowork(*obj);
    delete obj;
    return 0;
}

我得到的输出是

In cons
Do work
In dest
In dest

现在为什么构造函数被调用一次，而析构函数被调用两次？有人可以解释一下吗？

Now why does the constructor gets called once but the destructor is called twice?Can someone please explain this ?

谢谢

推荐答案

void Dowork(CTemp obj)

这里将执行local-copy，在退出 DoWork 函数，这就是为什么你看到析构函数调用。

Here local-copy will be done, that will be destruct after exit from scope of DoWork function, that's why you see destructor-call.

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