Can (a==1 && a==2 && a==3) evaluate to true in Java?

Question

We know it can in JavaScript.

But is it possible to print \"Success\" message on the condition given below in Java?

if (a==1 && a==2 &&am         


        

Answer 1

Using concepts (and code) from a brilliant code golf answer, Integer values can be messed with.

In this case, it can make ints casted to Integers be equal when they wouldn't normally be:

import java.lang.reflect.Field;

public class Test
{
    public static void main(String[] args) throws Exception
    {
        Class cache = Integer.class.getDeclaredClasses()[0];
        Field c = cache.getDeclaredField("cache");
        c.setAccessible(true);
        Integer[] array = (Integer[]) c.get(cache);
        // array[129] is 1
        array[130] = array[129]; // Set 2 to be 1
        array[131] = array[129]; // Set 3 to be 1

        Integer a = 1;
        if(a == (Integer)1 && a == (Integer)2 && a == (Integer)3)
            System.out.println("Success");
    }
}

Unfortunately it's not quite as elegant as Erwin Bolwidt's multithreaded answer (as this one requires Integer casting), but still some fun shenanigans take place.