条件语句未按预期运行：Javascript

Question

我正在尝试在用户和计算机之间制作一个小的石头、剪纸和剪刀程序。 除了 gameRound() 条件语句外，一切似乎都运行良好。 用户输入是什么并不重要。 它只是运行 (else) 语句。

 // a function that determines what the computer's choice is
    const getComputerChoice = () => {
        let compChoice = Math.random();
    
        if(compChoice > 0.5) {
            return "Rock";
        } else if(compChoice < 0.5) {
            return "scissors";
        } else if(compChoice == 0) {
            return "paper";
        }
    }
    
    // prompts the user to enter rock, paper or scissors
    let playerSelection = prompt();
    let computerSelection = getComputerChoice();
    
    // the logic that decides who wins and loses
    const gameRound = (playerSelection, computerSelection) => {
        if(playerSelection === "rock" && computerSelection === "rock" || playerSelection === "paper" && computerSelection === "paper" || playerSelection === "scissors" && computerSelection === "scissors") {
                return "It's a tie!!!";
        }  else if(playerSelection === "rock" && computerSelection === "paper")  {
                return "Computer wins!!!";
        }  else if(playerSelection === "rock" && computerSelection === "scissors")  {
                return "You win!!!";
        }  else if(playerSelection === "paper" && computerSelection === "scissors")  {
                return "Computer wins!!!";
        }  else if(playerSelection === "paper" && computerSelection === "rock")  {
                return "You win!!!";
        }  else if(playerSelection === "scissors" && computerSelection === "rock")  {
                return "Computer wins!!!";
        }  else if(playerSelection === "scissors" && computerSelection === "paper")  {
                return "You win!!!";
        }  else {
            return "Winner undecided";
        }
    }
    
    // the function that begins the game
    const game = () => {
        for(let i = 0; i < 5; i++) {
            return gameRound();
        }
    }
    
    console.log(game());

Answer 1

由于新声明的参数playerSelection和computerSelection ， gameRound条件语句无法按预期运行。 所以它必须是一个函数语句而不是内联箭头函数。

然后，Javascript代码如下：

// a function that determines what the computer's choice is
const getComputerChoice = () => {
    let compChoice = Math.random();

    if(compChoice > 0.5) {
        return "Rock";
    } else if(compChoice < 0.5) {
        return "scissors";
    } else if(compChoice == 0) {
        return "paper";
    }
}

// the logic that decides who wins and loses
function gameRound(playerSelection, computerSelection) {
    if(playerSelection === "rock" && computerSelection === "rock" || playerSelection === "paper" && computerSelection === "paper" || playerSelection === "scissors" && computerSelection === "scissors") {
            return "It's a tie!!!";
    }  else if(playerSelection === "rock" && computerSelection === "paper")  {
            return "Computer wins!!!";
    }  else if(playerSelection === "rock" && computerSelection === "scissors")  {
            return "You win!!!";
    }  else if(playerSelection === "paper" && computerSelection === "scissors")  {
            return "Computer wins!!!";
    }  else if(playerSelection === "paper" && computerSelection === "rock")  {
            return "You win!!!";
    }  else if(playerSelection === "scissors" && computerSelection === "rock")  {
            return "Computer wins!!!";
    }  else if(playerSelection === "scissors" && computerSelection === "paper")  {
            return "You win!!!";
    }  else {
        return "Winner undecided";
    }
}

// prompts the user to enter rock, paper or scissors
let playerSelection = prompt();
let computerSelection = getComputerChoice();

for (let i = 0; i < 5; i++) {
    console.log(gameRound(playerSelection, computerSelection));
}

或者如果你的意思是玩 5 轮剪刀石头布，那么playerSelection和computerSelection变量的分配应该在for循环内，如下所示：

// a function that determines what the computer's choice is
const getComputerChoice = () => {
    let compChoice = Math.random();

    if(compChoice > 0.5) {
        return "Rock";
    } else if(compChoice < 0.5) {
        return "scissors";
    } else if(compChoice == 0) {
        return "paper";
    }
}

// the logic that decides who wins and loses
function gameRound(playerSelection, computerSelection) {
    if(playerSelection === "rock" && computerSelection === "rock" || playerSelection === "paper" && computerSelection === "paper" || playerSelection === "scissors" && computerSelection === "scissors") {
            return "It's a tie!!!";
    }  else if(playerSelection === "rock" && computerSelection === "paper")  {
            return "Computer wins!!!";
    }  else if(playerSelection === "rock" && computerSelection === "scissors")  {
            return "You win!!!";
    }  else if(playerSelection === "paper" && computerSelection === "scissors")  {
            return "Computer wins!!!";
    }  else if(playerSelection === "paper" && computerSelection === "rock")  {
            return "You win!!!";
    }  else if(playerSelection === "scissors" && computerSelection === "rock")  {
            return "Computer wins!!!";
    }  else if(playerSelection === "scissors" && computerSelection === "paper")  {
            return "You win!!!";
    }  else {
        return "Winner undecided";
    }
}

for (let i = 0; i < 5; i++) {
    // prompts the user to enter rock, paper or scissors
    let playerSelection = prompt();
    let computerSelection = getComputerChoice();
    console.log(gameRound(playerSelection, computerSelection));
}