我必须使用#include< string>在< iostream>旁边 [英] Do I have to use #include <string> beside <iostream>?

问题描述

我开始学习C ++，我读了一本书，书中写道，我必须使用< string> 头文件，因为字符串类型不是直接构建到编译器中。
如果我使用< iostream> 我可以使用字符串类型。

I started learning C++ and I read a book which writes that I must use the <string> header file because the string type is not built directly into the compiler. If I use the <iostream> I can use the string type.

如果我包括< iostream> ，当我想使用字符串类型时，包括< string>

Do I have to include the <string> header when I want to use the string type if I included the <iostream> header? Why? Is there some difference?

推荐答案

是的，你必须包括你使用的东西。它不强制标准头包括彼此（有几个例外IIRC）。

Yes, you have to include what you use. It's not mandated that standard headers include one another (with a few exceptions IIRC). It might work now, but might fail on a different compiler.

在您的情况下，显然< iostream> 包括< string> ，直接或间接，但不要依赖它。

In your case, apparently <iostream> includes <string>, directly or indirectly, but don't rely on it.

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