如何在Java中正确使用add方法？

Question

I need to add the Rectangle to the ArrayList called bricks as you can see below.

private void drawBrick(int startX, int startY){

    new Rectangle();

    currentColor = 0;

    startX = 54;
    startY = 16;

    bricks = new ArrayList<Rectangle>();
    bricks.add("Rectangle");


}

I keep getting compilation errors after adding that that last line of code and this weird warning pops up saying "Some messages have been simplified; recompile with -Xdiags:verbose to get full output."

Anyone know what I've done wrong?

Answer 1

You can't just refer to the Rectangle you created by using "Rectangle" . Instead, you need to name the Rectangle when you create it and use that name later on, like this:

private void drawBrick(int startX, int startY) {
    Rectangle theRectangle = new Rectangle();

    currentColor = 0;

    startX = 54;
    startY = 16;

    bricks = new ArrayList<Rectangle>();
    bricks.add(theRectangle);
}

Notice how that creates a variable called theRectangle which is set equal to the Rectangle you create, then that specific Rectangle ( theRectangle ) is added to the ArrayList called bricks .