Difference between <string> and <string.h>?

问题

How come this code

std::map <std::string , int> m;
m[\"a\"]=1;

compiles with (I\'m using MSVC 2010)

#include <string>

but not with

#include <string.h>

?

回答1:

• <string.h> contains old functions like strcpy, strlen for C style null-terminated strings.
• <string> primarily contains the std::string, std::wstring and other classes.

回答2:

string.h is a C header not a C++ header, period!

回答3:

<string.h> is cstring - http://www.cplusplus.com/reference/clibrary/cstring/

<string> is the c++ string class - http://www.cplusplus.com/reference/string/

Edit per Nicol Bolas comment below and a bit of googling:

<cstring> will usually import the same things as <string.h> but into the std namespace. <string.h> will usually import everything into the global namespace. It appears to depend on the library implementation you're using though according to my googling.

Personally I only ever use <cstring> if I need C style string helpers.

回答4:

string.h is C's header file while string is C++'s header file.

回答5:

<string.h> contains C-library string functions. strlen, strcmp, etc.

<string> contains the definition for std::basic_string, which has the typedefs std::string and std::wstring. That's the difference.

They really have no relationship at all, outside of the fact that they both deal with strings.

回答6:

They are entirely different headers.

<string> is C++ string class

<string.h> or <cstring> defines functions to manipulate C strings and arrays

回答7:

As stated, string.h and cstring are C headers (while cstring is basically a C++ wrapper for string.h), containing functions for C strings, which are char[] terminated by '\0'. You want to use the c++ class string, which header is <string>.

回答8:

I believe <string.h> is just used for C and <string> for C++. So including string.h wont work.

回答9:

<string.h> is a C standard library header while <string> is a cpp in fact all the c standard header files have .h extension an non of cpp have .h.

来源：https://stackoverflow.com/questions/9257665/difference-between-string-and-string-h