javascript - 石头、布、剪刀、蜥蜴、Spock 在 JavaScript 中

Question

我是 JavaScript 的新手。我刚开始学习它，我决定制作一款“石头、剪刀、蜥蜴、史波克”游戏。这是代码:

var userChoice = prompt("Do you choose rock, paper, scissors, lizard, or spock?")
var computerChoice = Math.random();
if (computerChoice < 0.2) {
    computerChoice = "rock";
} else if (computerChoice <= 0.4) {
    computerChoice = "paper";
} else if (computerChoice <= 0.6) {
    computerChoice = "scissors";
} else if (computerChoice <= 0.8) {
    computerChoice = "lizard";
} else {
    computerChoice = "spock";
}

alert("The computer chose " + computerChoice);

var compare = function(choice1, choice2){
    if (choice1 === choice2) {
        alert("And... It's a tie!");
    }

//If the user chose rock...
else if (choice1 === "rock") {
    if (choice2 === "scissors") {
        alert("Rock wins!");
    } else if (choice2 === "paper") {
        alert("Paper wins!");
    } else if (choice2 === "lizard") {
        alert("Rock wins!");
    } else {
        alert("Spock wins!");
    }
}

//If the user chose paper...
else if (choice1 === "paper") {
    if (choice2 === "scissors") {
        alert("Scissors wins!");
    } else if (choice2 === "rock") {
        alert("Paper wins!");
    } else if (choice2 === "lizard") {
        alert("Lizard wins!");
    } else {
        alert("Paper wins!");
    }
}

//If the user chose scissors...
else if (choice1 === "scissors") {
    if (choice2 === "paper") {
        alert("Scissors wins!");
    } else if (choice2 === "rock") {
        alert("Rock wins!");
    } else if (choice2 === "lizard") {
        alert("Scissors wins!");
    } else {
        alert("Spock wins!");
    }
}

//If the user chose lizard...
else if (choice1 === "lizard") {
    if (choice2 === "scissors") {
        alert("Scissors wins!");
    } else if (choice2 === "rock") {
        alert("Rock wins!");
    } else if (choice2 === "paper") {
        alert("Lizard wins!");
    } else {
        alert("Lizard wins!");
    }
}

//If the user chose spock...
else if (choice1 === "spock") {
    if (choice2 === "scissors") {
        alert("Spock wins!");
    } else if (choice2 === "rock") {
        alert("Spock wins!");
    } else if (choice2 === "lizard") {
        alert("Lizard wins!");
    } else {
        alert("Paper wins!");
    }
}
};
compare(userChoice, computerChoice);

我想在我的代码中添加 2 个主要内容，但我不知道如何添加:

1. 现在，如果用户输入带有大写字母“R”的“Rock”，它不会被识别为五个有效输入之一(rock、paper、scissors、lizard 和斯波克)。有没有办法让它在用户输入有效的大写字母(或字母)时仍然有效？

2. 我想添加一些东西，这样每当有人输入无效的东西(例如“sloth”)时，它就会提醒他们输入无效，并会再次要求他们输入石头、布、剪刀、蜥蜴，或斯波克。

Answer 1

用数学简化结果函数。 http://jsfiddle.net/afrievalt/qBbJn/

var options = ["paper", "rock", "lizard", "spock", "scissors"],
  result = [" ties ", " beats ", " loses to "],
  bigBang = function(choice1, choice2) {
      var index1 = options.indexOf(choice1), //spock => 3
          index2 = options.indexOf(choice2), //rock=> 1
          dif = index2 - index1; // 1 - 3 => -2
      if(dif < 0) { // -2 < 0 => truthy
          dif += options.length; // -2 + 5 => 3
      }
      while(dif > 2) { //3 > 2 => truthy
          dif -= 2; // 3 - 2 => 1
      }
      return choice1 + result[dif] + choice2; //spock beats rock
  };

.

  bigBang("spock", "paper");  // spock losses to paper 

  var i = Math.floor(Math.random() * 5),
      randomChoice = options[i];
  bigBang(randomChoice, userChoice);

此函数也适用于 options = ["cockroach", "nuke", "shoe"](来自 70 年代的节目)或任何奇数长度数组，如 options = ["water", "fire", "paper ”、“岩石”、“树”、“金属”、“泥土”]//todo: 如果任何索引 = -1 则抛出错误