javascript - 为什么我玩石头、剪子、布、蜥蜴、史波克时没有说我赢了？

Question

我的游戏运行良好，除了当涉及蜥蜴或史波克时我赢了，我不明白为什么，因为当我输了时，它显示我输了，这是正确的。我试图查找拼写错误，但没有找到。如果有人能看出问题所在，我将不胜感激。

这是一个 fiddle ，以便您可以看到问题:http://jsfiddle.net/5RGwv/

这是我的 HTML:

<div id="center">

<button id="button" onclick="play()">Play</button>
<p>You rolled:</p><span id="myroll"></span>
<p>Your opponent rolled:</p><span id="opproll"></span>

<p id="outcome"></p>
</div>

Javascript:

function play() {

var ROCK = 0;
var PAPER = 1;
var SCISSORS = 2; 
var LIZARD = 3;
var SPOCK = 4;

var choices = ['rock', 'paper', 'scissors', 'lizard', 'spock'];

var myRoll = Math.floor(Math.random()*choices.length);
var opponentRoll = Math.floor(Math.random()*choices.length);

document.getElementById("myroll").innerHTML=choices[myRoll];
document.getElementById("opproll").innerHTML=choices[opponentRoll];

if (myRoll == opponentRoll) {
document.getElementById("outcome").innerHTML="It's a draw.";
return;
} //end of if

switch(myRoll) {

case ROCK:
    document.getElementById("outcome").innerHTML=(opponentRoll == SCISSORS ? 'You win!' : 'You lose!');
    return;

case ROCK:
    document.getElementById("outcome").innerHTML=(opponentRoll == LIZARD ? 'You win!' : 'You lose!');
    return;

case PAPER: 
    document.getElementById("outcome").innerHTML=(opponentRoll == ROCK ? 'You     win!' : 'You lose!');
    return;

case PAPER:
    document.getElementById("outcome").innerHTML=(opponentRoll == SPOCK ? 'You win!' : 'You lose!');
    return;

case SCISSORS:
    document.getElementById("outcome").innerHTML=(opponentRoll == PAPER ? 'You win!' : 'You lose!');
    return;

case SCISSORS:
    document.getElementById("outcome").innerHTML=(opponentRoll == LIZARD ? 'You win!' : 'You lose!');
    return;

case LIZARD:
    document.getElementById("outcome").innerHTML=(opponentRoll == SPOCK ? 'You win!' : 'You lose!');
    return;

case LIZARD:
    document.getElementById("outcome").innerHTML=(opponentRoll == PAPER ? 'You win!' : 'You lose!');
    return;

case SPOCK:
    document.getElementById("outcome").innerHTML=(opponentRoll == SCISSORS ? 'You win!' : 'You lose!');
    return;

case SPOCK:
    document.getElementById("outcome").innerHTML=(opponentRoll == ROCK ? 'You win!' : 'You lose!');
    return;

} //end of switch(myRoll)


} //end of play()

Answer 1

将您的 switch 语句替换为:

var result = false;
switch(myRoll) {
    case ROCK:
        result = opponentRoll == SCISSORS || opponentRoll == LIZARD;
        break;
    case PAPER: 
        result = opponentRoll == ROCK     || opponentRoll == SPOCK;
        break;
    case SCISSORS:
        result = opponentRoll == PAPER    || opponentRoll == LIZARD;
        break;
    case LIZARD:
        result = opponentRoll == SPOCK    || opponentRoll == PAPER;
        break;
    case SPOCK:
        result = opponentRoll == SCISSORS || opponentRoll == ROCK;
        break;
}

document.getElementById("outcome").innerHTML = result ?  'You win!' : 'You lose!';

这段代码使用开关仅来检查您是否获胜。然后，最后设置该值。

既然如果你投“石头”而对手投“剪刀”或“蜥蜴”，你就赢了，所以我将这些陈述结合起来。

您可以通过仅检查 win 案例来进一步缩短代码，如下所示:

var result =  myRoll == ROCK     && (opponentRoll == SCISSORS || opponentRoll == LIZARD) ||
              myRoll == PAPER    && (opponentRoll == ROCK     || opponentRoll == SPOCK)  ||
              myRoll == SCISSORS && (opponentRoll == PAPER    || opponentRoll == LIZARD) ||
              myRoll == LIZARD   && (opponentRoll == PAPER    || opponentRoll == SPOCK)  ||
              myRoll == SPOCK    && (opponentRoll == ROCK     || opponentRoll == SCISSORS);

document.getElementById("outcome").innerHTML = result ?  'You win!' : 'You lose!';

如果这 5 行中的任何一行为 true，您就赢了。