“+” operator for Java-classes

Question

I have a class like this:

private static class Num {
    private int val;

    public Num(int val) {
        this.val = val;
    }
}

Is it

Answer 1

There is no operators overloading in java. The only thing which is supported for objects, is string concatenations via "+". If you have a sequences of objects joined via "+" and at least one of them is a String, then the result will be inlined to String creation. Example:

Integer a = 5;
Object b = new Object();

String str = "Test" + a + b;

will be inlined to

String str = new StringBuilder("Test").append(a).append(b).toString();