Testing if colors equal

问题:

I'm working on the Breakout assignment from the Stanford lectures on iTunes U (still pretty green) and ran into a snarl. I'm trying to set a point value for the different colored bricks so I can calculate a score but my if's don't seem to work. I have a feeling that getColor() isn't returning the value that I think it is; I created a status label to show my what it's returning but I still can't figure out how to test for that. More than likely it's something simple I'm missing or just don't know of yet.

Here's a snippet of the bit I'm working on:

if (collider != null && collider != paddle) {
        remove(scoreLabel);
        vy = -vy;
        Color brickColor = collider.getColor();
        add(new GLabel("" + collider.getColor(), 10, 12));
        double temp = brickVal(brickColor) * scoreMultiplier;
        score += Math.abs(temp);
        addScoreboard();
        remove(collider);
    }
}

private double brickVal(Color c) {
    if (c.equals(Color.RED)) {
        return 10.0;
    } else if (c == Color.ORANGE) {
        return brickVal = 8.0;
    } else if (c == Color.YELLOW) {
        return brickVal = 6.0;
    } else if (c == Color.GREEN) {
        return brickVal = 4.0;
    } else if (Color.CYAN.equals(c)) {
        return brickVal = 2.0;
    } else if (c == Color.MAGENTA) {
        return brickVal = 1.0;
    } else {
        return 1.0;
    }
}

If you need the full code let me know.

回答1:

Use Color.X.equals(c) for your if cases that are like c == Color.X. You're testing if the objects are the same instance, instead of if they're considered to be equal to each other.

You could also use c.equals(Color.X) like you did for Color.RED, however many people prefer the other way to safeguard against a NullPointerException for cases where c is null.