是否有任何理由在删除之前检查 NULL 指针?

2021-12-13 00:00:00 pointers null c++ delete-operator

我经常看到遗留代码在删除指针之前检查NULL,类似于,

I often see legacy code checking for NULL before deleting a pointer, similar to,

if (NULL != pSomeObject) 
{
    delete pSomeObject;
    pSomeObject = NULL;
}

是否有任何理由在删除之前检查 NULL 指针?之后将指针设置为NULL的原因是什么?

Is there any reason to checking for a NULL pointer before deleting it? What is the reason for setting the pointer to NULL afterwards?

推荐答案

删除空指针是完全安全"的;它实际上相当于一个空操作.

It's perfectly "safe" to delete a null pointer; it effectively amounts to a no-op.

您可能希望在删除之前检查 null 的原因是尝试删除空指针可能表明您的程序中存在错误.

The reason you might want to check for null before you delete is that trying to delete a null pointer could indicate a bug in your program.

编辑

注意:如果重载删除操作符,删除NULL

NOTE: if you overload the delete operator, it may no longer be "safe" to delete NULL

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