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

Do not confound the preincrement operator ++ and the unary operator + repeated twice.

int e = ++10; // won't compile "invalid argument to operation ++/--"
int e = + +10; //compile and e equals to 10