std::string 到 char*

2022-01-12 00:00:00 string char c++

我想将 std::string 转换为 char* 或 char[] 数据类型.

I want to convert a std::string into a char* or char[] data type.

std::string str = "string";
char* chr = str;

导致:错误:无法将‘std::string’转换为‘char’...".

有哪些方法可以做到这一点?

What methods are there available to do this?

推荐答案

它不会自动转换(谢天谢地).您必须使用方法 c_str() 来获取 C 字符串版本.

It won't automatically convert (thank god). You'll have to use the method c_str() to get the C string version.

std::string str = "string";
const char *cstr = str.c_str();

注意它返回一个 const char *;您不能更改 c_str() 返回的 C 风格字符串.如果你想处理它,你必须先复制它:

Note that it returns a const char *; you aren't allowed to change the C-style string returned by c_str(). If you want to process it you'll have to copy it first:

std::string str = "string";
char *cstr = new char[str.length() + 1];
strcpy(cstr, str.c_str());
// do stuff
delete [] cstr;

或者在现代 C++ 中:

Or in modern C++:

std::vector<char> cstr(str.c_str(), str.c_str() + str.size() + 1);

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