删除与删除[]

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释放内存: delete []等于 delete 吗

当我学习 C + + 的时候，这已经是很久以前的事了。我被告知永远不要使用 delete，但是 delete[]在单个对象上执行 delete[]将等同于 delete。知道不要太相信老师，我想知道，这是真的吗？

调用 delete而不是 delete[]有什么理由吗？

我已经扫描了可能相关的问题，但没有找到任何明确的答案。

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小开

delete is used to delete a single object, while delete[] is used to delete an array of objects. Check this link for more info.

小开

No! you call delete[] when you allocate with new[], otherwise you call delete.

What teacher told you leads to undefined behaviour and, if you are lucky, an application crash.

小开

最佳答案

From the standard (5.3.5/2) :

In the first alternative (delete object), the value of the operand of delete shall be a pointer to a non-array object or a pointer to a sub-object (1.8) representing a base class of such an object (clause 10). If not, the behavior is undefined.

In the second alternative (delete array), the value of the operand of delete shall be the pointer value which resulted from a previous array new-expression. If not, the behavior is undefined.

So no : they are in no way equivalent !

小开

delete [] is "vector delete" and corresponds to vector new, i.e. new[].

You must use the matching pair of allocators. E.g. malloc/free, new/delete, new[]/delete[], else you get undefined behavior.