Question

作为输出，“播放器卡”应该随机选择套装和值输出，但不是我的代码。

是否有遗漏或我的if ... else语句搞砸了？我知道我可以使用do ... while，但我希望能够使用if ... else语句。

public static void main(String[] args){

    //A new object, player card for the card suit.
    Card player = new Card();

    //Setting the suit for player card to be displayed randomly
    player.setSuit((int) (Math.random()*4));

    //Setting the value for player card to be displayed randomly 
    player.setValue(1 + (int)(Math.random()*12));

    //A new object, computer card for the card suit
    Card comp = new Card();

    //Setting the suit for computer card to be displayed randomly
    comp.setSuit((int) (Math.random()*4));

    //Setting the value for computer card to be displayed randomly
    comp.setValue(1 + (int)(Math.random()*12));


    if((comp.getValue()== player.getValue()) && (comp.getSuit() == player.getSuit()))
        System.out.println("Player Card: " + player.getValueString() + " of " + player.getSuitString());
        System.out.println("Computer Card: " + comp.getValueString() + " of " + comp.getSuitString());
        if(player.getValue() > comp.getValue())
            System.out.println("Player won!");
        else if(player.getValue() < comp.getValue())
            System.out.println("Computer won!");
        else
            System.out.println("Tie!");

Answer 1

这看起来更好：

if(comp.getValue() == player.getValue())
    System.out.println("Tie!");
else if(player.getValue() > comp.getValue())
    System.out.println("Player won!");
else if(player.getValue() < comp.getValue())
    System.out.println("Computer won!");

另外，如果你不使用括号（if { .. } else { .. }），只有if语句下面的第一行将在if中执行。

Answer 2

您的代码只会输出播放器和计算机的卡片，如果它们完全相同的话。改变这个：

if((comp.getValue()== player.getValue()) && (comp.getSuit() == player.getSuit()))
        System.out.println("Player Card: " + player.getValueString() + " of " + player.getSuitString());
        System.out.println("Computer Card: " + comp.getValueString() + " of " + comp.getSuitString());
        if(player.getValue() > comp.getValue())
            System.out.println("Player won!");
        else if(player.getValue() < comp.getValue())
            System.out.println("Computer won!");
        else
            System.out.println("Tie!");

对此：

System.out.println("Player Card: " + player.getValueString() + " of " + player.getSuitString());
System.out.println("Computer Card: " + comp.getValueString() + " of " + comp.getSuitString());
if((comp.getValue()== player.getValue()) && (comp.getSuit() == player.getSuit()))
        // handle redrawing cards here
if(player.getValue() > comp.getValue())
    System.out.println("Player won!");
else if(player.getValue() < comp.getValue())
    System.out.println("Computer won!");
else
    System.out.println("Tie!");

Answer 3

尝试使用括号来确定每种情况下的内容，这样就不会迷路。

Answer 4

长if条件之后的第一行只有在你为玩家和comp获得的随机卡匹配时才会执行，这是不太可能的。你究竟想要实现什么目标？

你应该完全删除那一行（它存在的原因是什么？）：

if((comp.getValue()== player.getValue()) && (comp.getSuit() == player.getSuit()))

Answer 5

根据我对你的问题的理解，你有错误的条件。正如你现在拥有的那样，只有当计算机和玩家卡完全相同时才会匹配。

尝试类似：

 if(comp != null && player != null){
  System.out.println("Player Card: " + player.getValueString() + " of " + player.getSuitString());
  System.out.println("Computer Card: " + comp.getValueString() + " of " + comp.getSuitString());

  if(player.getValue() > comp.getValue())
        System.out.println("Player won!");
    else if(player.getValue() < comp.getValue())
        System.out.println("Computer won!");
    else
        System.out.println("Tie!");
}

Answer 6

没有分析太多，但在我看来你想要一些块在里面但是你忘了{ }制作那些块，不是吗？

Answer 7

If语句将应用于大括号后面的代码块

if(condition){
thenDoSomething();
thenDoSomethingElse();
}

如果没有花括号，则只有下一个语句将应用于If

if(condition)
thisWillRunIfConditionIsTrue();
thisWillAlwaysRun();

您的代码没有花括号，因此播放器输出只会在与计算机输出匹配时打印，而计算机输出将始终打印。

     if((comp.getValue()== player.getValue()) && (comp.getSuit() == player.getSuit())) 
            System.out.println("Player Card: " + player.getValueString() + " of " + player.getSuitString());  
            System.out.println("Computer Card: " + comp.getValueString() + " of " + comp.getSuitString());

Answer 8

第一个'if'评估为false，所以行：

System.out.println("Player Card: " + player.getValueString() + " of " + player.getSuitString());

永远不会调用

（除非值和套装都相等）。

您的代码看起来像这样：

if((comp.getValue()== player.getValue()) && (comp.getSuit() == player.getSuit())) {

System.out.println("Player Card: " + player.getValueString() + " of " + player.getSuitString());

}

System.out.println("Computer Card: " + comp.getValueString() + " of " + comp.getSuitString());

始终使用带有'if'语句的大括号。

java：if ... else语句在我的代码中可能不正确

8 个答案: