Java Help. Coin code

Question

I'm doing a code that wants me to take this code and instead of storing as an int, store it as a boolean

public class Coin {

    private final int HEADS = 0;
    private final int TAILS = 1; 

    private int face;

    //------------------------------------------
    // Sets up the coin by flipping it initially
    //------------------------------------------
    public Coin () {
        flip(); 
    }

    //-------------------------------------------------
    // Flips the coin by randomly choosing a face value.
    //-------------------------------------------------
    public void flip() {
        face = (int) (Math.random() * 2); 
    }

    //-----------------------------------------------------
    //Returns true of the current face of the coin is heads
    //-----------------------------------------------------
    public boolean isHeads () {
        return (face == HEADS); 
    }

    //------------------------------------------------
    //Returns the current face of the coin as a string
    //------------------------------------------------
    public String toString() {
        String faceName;
        if (face == HEADS)
            faceName = "Heads";
        else
            faceName = "Tails"; 
        return faceName; 
    }
}

I have this but don't know what to change the bottom else statement to. It says its wrong.

public class Coin2 {

    private final boolean HEADS = false; 
    private final boolean TAILS = true;

    private boolean face;

    //------------------------------------------
    // Sets up the coin by flipping it initially
    //------------------------------------------
    public Coin2 () {
        flip(); 
    }

    //-------------------------------------------------
    // Flips the coin by randomly choosing a face value.
    //-------------------------------------------------
    public void flip() {
        face = (boolean) (Math.random() < 2); 
    }

    //-----------------------------------------------------
    //Returns true of the current face of the coin is heads
    //-----------------------------------------------------
    public boolean isHeads () {
        return (face == false);
    }

    //-----------------------------------------------
    //Returns the current face of the coin as a string
    //------------------------------------------------
    public String toString() {
        String faceName;
        if (face == false);
            faceName = "Heads";
        else
            faceName = "Tails"; 
            return faceName; 
    }
}

score 2 · Answer 1 · answered Mar 22 '15 at 21:12

Looks like you have a semicolon that should not be there on the if statment

if (face == false);
        faceName = "Heads";
        else faceName = "Tails"; 
    return faceName;

Should read

if (face == false)
    faceName = "Heads";
else 
    faceName = "Tails"; 
return faceName;

(also formatted for readability)

candied_orange · Answer 2 · 2015-03-24T20:25:15.327

You will get more interesting flip results if you make this change:

public void flip() {
    face = Math.random() < .5; 
}

Because as random()s javadoc says:

Returns a double value with a positive sign, greater than or equal to 0.0 and less than 1.0.

The (boolean) cast wasn't needed so I took it out.

This next one is a nasty bug:

if (face == false);
        faceName = "Heads";
        else faceName = "Tails"; 
    return faceName;

A semicolon at the end of an if is such a pain to spot and debug that most programmers follow a style guideline that helps keep it from happening. It looks like this:

if (face == false) {
    faceName = "Heads";
}
else {
    faceName = "Tails"; 
}
return faceName;

Always use the curly braces and it should stop this extra semicolon nightmare from happening again. Also be careful with indentation. Messing it up will mess with your brain.

Java Help. Coin code

2 Answers2