Java - compareTo and operators

Question

If I have a class Person that implements Comparable (compares personA.height to personB.height, for example), is it possible to use

    personA < personB

as a substitute for

    personA.compareTo(personB) == -1? 

Are there any issues in doing this or do I need to overload operators?

Answer 1

No, it isn't possible to use personA < personB as a substitute. And you can't overload operators in Java.

Also, I'd recommend changing

personA.compareTo(personB) == -1

to

personA.compareTo(personB) < 0

What you have now probably works for your class. However, the contract on compareTo() is that it returns a negative value when personA is less than personB. That negative value doesn't have to be -1, and your code might break if used with a different class. It could also break if someone were to change your class's compareTo() method to a different -- but still compliant -- implementation.

Answer 2

It is not posible, java does not give you operator overload.
But a more OO option is to add a method inside person

public boolean isTallerThan(Person anotherPerson){
    return this.compareTo(anotherPerson) > 0;
}

so instead of writing

if(personA.compareTo(personB) > 0){

}

you can write

if(personA.isTallerThan(personB)){

}

IMHO it is more readable because it hides details and it is expressed in domain language rather than java specifics.