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

There is another way to approach this (in additional to the volatile data-racing approach that I posted earlier), using the power of PowerMock. PowerMock allows methods to be replaced with other implementations. When that is combined with auto-unboxing, the original expression (a == 1 && a == 2 && a == 3), without modification, can be made true.

@phflack's answer relies on modifying the auto-boxing process in Java that uses the Integer.valueOf(...) call. The below approach relies on modifying auto-unboxing by changed the Integer.intValue() call.

The advantage of the below approach is that the original if-statement given by the OP in the question is used unchanged, which I think is the most elegant.

import static org.powermock.api.support.membermodification.MemberMatcher.method;
import static org.powermock.api.support.membermodification.MemberModifier.replace;

import java.util.concurrent.atomic.AtomicInteger;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

@PrepareForTest(Integer.class)
@RunWith(PowerMockRunner.class)
public class Ais123 {
    @Before
    public void before() {
        // "value" is just a place to store an incrementing integer
        AtomicInteger value = new AtomicInteger(1);
        replace(method(Integer.class, "intValue"))
            .with((proxy, method, args) -> value.getAndIncrement());
    }

    @Test
    public void test() {
        Integer a = 1;

        if (a == 1 && a == 2 && a == 3) {
            System.out.println("Success");
        } else {
            Assert.fail("(a == 1 && a == 2 && a == 3) != true, a = " + a.intValue());
        }
    }

}