Assertions - Finding the output Questions and Answers

The program is run with java -ea Trial81 - what will be the output?

public class Trial81
{
    interface Greeter
    {
        default String greet()
        {
            assert name() != null : "name was null";
            return "hi " + name();
        }
        String name();
    }

    public static void main(String[] args)
    {
        Greeter g = () -> null;
        System.out.println(g.greet());
    }
}

The program is run with java -ea Case82 - what will be the output?

public class Case82
{
    public static void main(String[] args) throws Exception
    {
        Thread t = new Thread(new Runnable()
        {
            public void run()
            {
                assert false : "in thread";
            }
        });
        t.start();
        t.join();
        System.out.println("main done");
    }
}

The program is run with java -ea Sketch83 - what will be the output?

public class Sketch83
{
    int v;

    {
        v = 1;
        assert v == 1;
    }

    Sketch83()
    {
        assert v == 1;
        v = 2;
    }

    public static void main(String[] args)
    {
        System.out.println(new Sketch83().v);
    }
}

The program is run with java -ea Item84 - what will be the output?

public class Item84
{
    public static void main(String[] args)
    {
        outer:
        for (int i = 0; i < 3; i++)
        {
            for (int j = 0; j < 3; j++)
            {
                if (j == 1) continue outer;
                assert j == 0 : j;
                System.out.print(i);
            }
        }
    }
}

The program is run with java -ea Sample85 - what will be the output?

public class Sample85
{
    public static void main(String[] args)
    {
        int i = 0;
        do
        {
            i++;
        }
        while (i < 0);
        assert i == 0 : i;
        System.out.println(i);
    }
}

The program is run with java -ea Probe86 - what will be the output?

public class Probe86
{
    public static void main(String[] args)
    {
        try
        {
            int[] a = new int[1];
            a[2] = 0;
        }
        catch (ArrayIndexOutOfBoundsException e)
        {
            assert e.getMessage() == null : "has a message";
            System.out.println("handled");
        }
    }
}

The program is run with java -ea Fragment90 - what will be the output?

import java.util.*;

public class Fragment90
{
    public static void main(String[] args)
    {
        assert Objects.equals(null, null);
        System.out.println(Objects.equals("a", null));
    }
}

The program is run with java -ea Example91 - what will be the output?

public class Example91
{
    public static void main(String[] args)
    {
        assert Boolean.parseBoolean("TRUE");
        System.out.println(Boolean.parseBoolean("yes"));
    }
}

The program is run with java -ea Trial93 - what will be the output?

public class Trial93
{
    public static void main(String[] args)
    {
        Object o = true ? Integer.valueOf(1) : Double.valueOf(2.0);
        assert o instanceof Integer;
        System.out.println(o);
    }
}

The program is run with java -ea Case94 - what will be the output?

public class Case94
{
    public static void main(String[] args)
    {
        String s = "abc";
        s.toUpperCase();
        assert s.equals("ABC");
        System.out.println(s);
    }
}