Question

I’m taking a Java assessment test. I do not understand the use of the colon in the command line. Could someone please elaborate? Thanks.

Here is the question…

Given:

class One {
    int x = 0;
    {assert x == 1;}
}
public class Two {
    public static void main(String[] args) {
        int y = 0;
        assert y == 0;
        if(args.length > 0)
            new One();
    }
}

Which of the following will run without error? (Choose all that apply.)

A. java Two
B. java Two x
C. java -ea Two
D. java -ea Two x
E. java -ea:One Two
F. java -ea:One Two x
G. java -ea:Two Two x

Answer 1

The -ea is a command line argument to enables assertions. If you give a class after the -ea, it is enabled just for the classes listed. e.g. -ea:One turns on assertions for class One