“新”和“新”之间的区别是什么？和“malloc”和“calloc”在C ++？ [英] What is the difference between "new" and "malloc" and "calloc" in C++?

问题描述

new和malloc和calloc和其他人在家庭中有什么区别？

What is the difference between "new" and "malloc" and "calloc" and others in family?

（何时）

推荐答案

> new 和 delete 是C ++特有的功能。他们不存在于C. malloc 是老学校C做事的方式。大多数情况下，您不需要在C ++中使用它。

new and delete are C++ specific features. They didn't exist in C. malloc is the old school C way to do things. Most of the time, you won't need to use it in C++.

• malloc 分配未初始化的内存。必须使用 free 发布分配的内存。


• calloc malloc ，但用常量（0）初始化分配的内存。需要释放 free 。


• new 初始化分配的内存通过调用构造函数（如果它是一个对象）。分配有 new 的内存应该使用 delete （这反过来又调用析构函数）释放。它不需要您手动指定所需的大小，并将其转换为适当的类型。因此，它更现代，更不容易出错。

• malloc allocates uninitialized memory. The allocated memory has to be released with free.
• calloc is like malloc but initializes the allocated memory with a constant (0). It needs to be freed with free.
• new initializes the allocated memory by calling the constructor (if it's an object). Memory allocated with new should be released with delete (which in turn calls the destructor). It does not need you to manually specify the size you need and cast it to the appropriate type. Thus, it's more modern and less prone to errors.

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