Implentation of String class with rule of three

String.cpp

#include<iostream>
#include<cstring>

//Implentation of String class with rule of three 
class String 
{
    public:
        
        String(const char* args)
        : data_(new char[std::strlen(args) + 1]), length_(std::strlen(args))
        {
          std::strcpy(data_,args);
        }

        
        String(const String& that) // copy constructor
        {
            copyOther();
        }

        //assignment operator
        /*
           Handles the following cases
           1.   Self-assignment
                MyClass one;
                one = one;
          2. Operator must yield result
                MyClass one, two, three;
                three = two = one;
        */
        String& operator=(const String& other) { 
            
            if(this != &other) {    // To handle self-assignment
                clear();
                copyOther ();
            }
            return *this;
        }

        ~String() //destructor
        {
            clear()
        }

        //helper function
        void copyOther() {
            data_ = new char[std::strlen(that.data_) + 1];
            std::strcpy(data_, that.data_);
            length_ = that.length_;
        } 

        void clear() {
          delete[] data_;
        }


    private :
        char* data_;
        size_t length_;
        //String& operator=(const String&);
        //String(const String& that);
};

int main () {

}