引用不能为NULL或可以为NULL？ [英] A reference can not be NULL or it can be NULL?

问题描述

我已从维基百科中读取：

I have read from the Wikipedia that:

引用不能为空，而指针则可以;每个引用指的是一些对象，虽然它可能或不是有效的。

"References cannot be null, whereas pointers can; every reference refers to some object, although it may or may not be valid."

但是我不相信因为下面的代码看看它编译器没有错误：

But I don’t believe because of following code look at it compiler gives no error:

class person
{
public:
virtual void setage()=0;
};
main()
{
person *object=NULL;
person &object1=*object;
}

请详细说明这一点。

推荐答案

person& object1 = * object 与说 person& ; object1 = NULL 。可能编译器只是不够聪明，发现你是解引用空指针，但你会得到一个运行时错误。所以他们是一种真实的;）

Saying person &object1=*object is not the same thing as saying person &object1=NULL. Probably the compiler is just not smart enough to find out that you are dereferencing null pointer, but you'll get a runtime error anyway. So they are kind of true still ;)

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