Question

I am getting compilation error in Line 3, Is it any special case for asserts in java ? i am not sure why it’s expecting some return type from methodB() , can somebody help me here ? Thanks

public class AssertTest {
    public void methodA(int i) {
        assert i >= 0 : methodB();
        System.out.println(i);
    }

    public void methodB() {
        System.out.println("The value must not be negative");
    }

    public static void main(String args[]) {
        AssertTest test = new AssertTest();
        test.methodA(-10);
    }
}

Answer 1

The second form of the assertion statement is:

assert Expression1 : Expression2 ; 

where:

Expression1 is a boolean expression. Expression2 is an expression that
has a value. (It cannot be an invocation of a method that is declared
void.)

http://download.oracle.com/javase/1.4.2/docs/guide/lang/assert.html

Basically, Expression2 must return a value, not void.