convert a char* to std::string

Question

I need to use an std::string to store data retrieved by fgets(). To do this I need to convert the char* return value from fgets() into an std::string to store in an array. How can this be done?

Answer 1

std::string has a constructor for this:

const char *s = "Hello, World!"; std::string str(s); 

Note that this construct deep copies the character list at s and s should not be nullptr, or else behavior is undefined.

Answer 2

If you already know size of the char*, use this instead

char* data = ...; int size = ...; std::string myString(data, size); 

This doesn't use strlen.

EDIT: If string variable already exists, use assign():

std::string myString; char* data = ...; int size = ...; myString.assign(data, size);