Why does this Java code with “+ +” compile?

Question

I\'m curious why this simple program could be compiled by java using IntelliJ (Java 7).

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


        

Answer 1

The +'es are the unary plus operator, indicating sign of the value to the right of it, not the addition operator used when adding two values.

Consider this line

int e = + + + + + + + + 10;

which is equivalent to this

int e = +( +( +( +( +( +( +( +10)))))));

which again is equivalent to this

int e = +10;

and is similar (in form) to

int e = -10;

which probably is more straightforwardly understandable.

And by the way, + + is not equivalent, nor evaluated by the parser as the increment operator ++!