How is the string format used in C++?

6 months ago

2 minutes

In C++, there are no built-in string formatting functions, but you can use other methods to format strings. One common method is to use the std::stringstream class to create a string stream, then write the data that needs to be formatted into the stream. For example:

#include <iostream>
#include <string>
#include <sstream>

int main() {
    int num = 42;
    double pi = 3.14159;
    std::string name = "Alice";

    std::stringstream ss;
    ss << "Number: " << num << ", Pi: " << pi << ", Name: " << name;

    std::string formattedString = ss.str();

    std::cout << formattedString << std::endl;

    return 0;
}

In this example, we use the std::stringstream class to format an integer, a double precision floating point number, and a string into one string. Finally, we obtain the formatted string by calling ss.str() method.

In addition, C++11 introduces the std::to_string function, which makes it easy to convert basic data types to strings. For example:

int num = 42;
std::string numStr = std::to_string(num);

This method is suitable for converting basic data types such as integers and floating point numbers into strings.