java - Making a concat operator to add char array to a string. Printing a reference variable of a string object

You are trying to print an Object :

System.out.println(hello);  // right now this prints MyString@558ee9d6

In this case your MyString class

Make the get method to your variable oneString.

public String getOneString() {return this.oneString;}

and then call

System.out.println(hello.getOneString());

Another problem

System.out.println(hello.concat(goodbye));

You concat method receives a string and not a MyString class

You may want to do this

System.out.println(hello.concat(goodbye.getOneString()));

or

public String concat ( MyString myS)
    {
        String s = myS.getOneString();
        String result = oneString + s;
        return result;
    }

Final result:

public class Tester { public static void main (String[] args)

    {
    MyString hello = new MyString("hello");
    System.out.println(hello.getOneString());
    System.out.println(hello.getOneString().charAt(0)); 
    char[] arr = {'g','o','o','d','b','y','e' };
    MyString goodbye = new MyString(arr);
    System.out.println(hello.concat(goodbye.getOneString()));

    System.out.println(hello.equals(goodbye)); // works, prints false
    System.out.println(hello.equals(hello));  //works, prints true
    }
    }