Question

I wonder if there is a way to make an own conversion to integer in java. I mean a solution that is comparable to the implementation of the string conversion (toString). I want my class to be interpreted as integer in equation without calling a special function.

class MyClass(){
   private int number;

   MyClass(int n){
      this.number = n; 
   }

   public int toInteger(){
       return number
   }
}

usage:

MyClass a = new MyClass(2);
int result = 1+a;

result would be 3.

Answer 1

You’re describing operator overloading, and it’s not possible in Java. The closest thing would be subclassing Number, but + doesn’t work with it. For Strings + works because it has been built in as a special case in the language. There’s no way to extend + to work with anything else.

Of course, with your class, int result = 1 + a.toInteger(); works. Just a little extra work.