Question

在我的弹跳球程序中，它要求用户插入一些球，这些球将显示在屏幕上，然后从画布顶部开始，然后在画布底部的一条线上弹回。 / p>

当 finish = true 时，动画将停止。到目前为止，一旦第一个球的X位置超过550，动画就会停止。当每个球的X位置超过550时，如何使动画结束呢？

public void multiBounce(int numBalls)
{
    BouncingBall[] balls;
    balls = new BouncingBall[numBalls];

    int x = 50;
    int y = 150;

    for (int i = 0; i < balls.length; i++){


          balls[i] = new BouncingBall(x, y, 16, Color.blue, ground, myCanvas);
          x = x + 20;
          y = y - 30;
          balls[i].draw();  
    }

    boolean finished =  false;

    while(!finished) {

     for (int i = 0; i < balls.length; i++){

           balls[i].move();

    }

     for (int i = 0; i < balls.length; i++){
         if (balls[i].getXPosition() >= 550){

             finished = true;

        }
    }
}

Answer 1

只需检查每个球是否超出您想要的位置。此代码段应该可以完成这项工作。只需用下面的代码替换最后一个for循环。

finished=true;
for (int i = 0; i < balls.length; i++){ 
    if (balls[i].getXPosition() >= 550){  
        finished = finished && true; }
    else{
        finished=false;
        break;
    } 
}

Answer 2

您应该使用break语句。当它在loop内遇到时，loop立即终止，程序控制在loop之后的下一个语句处恢复。有关详细信息，请参阅Branching Statements

public void multiBounce(int numBalls)
    {
        BouncingBall[] balls;
        balls = new BouncingBall[numBalls];

        int x = 50;
        int y = 150;

        for (int i = 0; i < balls.length; i++){


            balls[i] = new BouncingBall(x, y, 16, Color.blue, ground, myCanvas);
            x = x + 20;
            y = y - 30;
            balls[i].draw();
        }

        boolean finished =  false;

        while(!finished) {

            for (int i = 0; i < balls.length; i++){

                balls[i].move();

            }

            for (int i = 0; i < balls.length; i++){
                if (balls[i].getXPosition() < 550){
                    finished = false;
                    break;
                }
                else {
                    finished = true;
                }
            }

            }
        }

一旦数组中的最后一个元素满足条件，如何使循环结束？

2 个答案: