java - Switch 执行所有的 case 语句

Question

有人能解释一下为什么我的循环是从 0 到 7 吗？我只需要获取前 3 种情况，但程序会遍历所有。代码在 show() 方法中。

for(brojac=0; brojac<3; brojac++){

    switch(brojac){
    case 1:
        figura1.setPosition(pomx[random], pomy[random]);
        stage.addActor(figura1);
        System.out.println("1");
    case 2:
        figura2.setPosition(pomx[random], pomy[random]);
        stage.addActor(figura2);
        System.out.println("2");
    case 3:
        figura3.setPosition(pomx[random], pomy[random]);
        stage.addActor(figura3);
        System.out.println("3");
    case 4:
        figura4.setPosition(pomx[random], pomy[random]);
        stage.addActor(figura4);
        System.out.println("4");
    case 5:
        figura5.setPosition(pomx[random], pomy[random]);
        stage.addActor(figura5);
        System.out.println("5");
    case 6:
        figura6.setPosition(pomx[random], pomy[random]);
        stage.addActor(figura6);
        System.out.println("6");
    case 7:
        figura7.setPosition(pomx[random], pomy[random]);
        stage.addActor(figura7);
        System.out.println("7");

    }
}

Answer 1

因为缺少中断。在每种情况下你都需要 break 关键字。有关详细说明，请参阅 switch statement java tutorial

例如

for(brojac=0; brojac<3; brojac++){

switch(brojac){
case 1:
    figura1.setPosition(pomx[random], pomy[random]);
    stage.addActor(figura1);
    System.out.println("1");
    break; /// Break here

case 2:
    figura2.setPosition(pomx[random], pomy[random]);
    stage.addActor(figura2);
    System.out.println("2");
    break; /// Break here
case 3:
    figura3.setPosition(pomx[random], pomy[random]);
    stage.addActor(figura3);
    System.out.println("3");
    break; /// Break here
case 4:
    figura4.setPosition(pomx[random], pomy[random]);
    stage.addActor(figura4);
    System.out.println("4");
    break; /// Break here
case 5:
    figura5.setPosition(pomx[random], pomy[random]);
    stage.addActor(figura5);
    System.out.println("5");
    break; /// Break here
case 6:
    figura6.setPosition(pomx[random], pomy[random]);
    stage.addActor(figura6);
    System.out.println("6");
    break; /// Break here
case 7:
    figura7.setPosition(pomx[random], pomy[random]);
    stage.addActor(figura7);
    System.out.println("7");
    break; /// Break here
}
}

否则，如果上述情况之一被评估为真，则将执行其他情况。