Question

Is it possible to create String class with String.cpp and String.h in c++ stl project?

String.h

#include <string> 
class String {
public:
    static std::string Replace(const std::string& str, const std::string& oldValue, const std::string& newValue);
};

There are compilation errors unless the class is renamed to something else like Stringy

Answer 1

Instead of a class with only static members, you use a namespace in C++.

#include <string>

namespace String {
    std::string Replace(const std::string& str, const std::string& oldValue, const std::string& newValue);
};