Javascript - Rock, Paper, Scissors (odinProject) Helpppp答案

【问题标题】：Javascript - Rock, Paper, Scissors (odinProject) HelppppJavascript - Rock, Paper, Scissors (odinProject) Helpppp
【发布时间】：2020-08-07 10:06:45
【问题描述】：

我在用 javascript 创建一个石头、剪纸、剪刀游戏的任务时遇到了麻烦（来自 odinproject.com 的任务）。每当我使用摇滚作为我的输入时，它似乎工作得很好。但是，当输入纸张或剪刀时，它不能正常工作。请任何帮助、建议和建议将不胜感激。我在这方面还很陌生，渴望了解更多！

谢谢！

这是我的代码：

function userChoice() {
  const userChoice = prompt("Do you choose Rock, Paper, or Scissors?").toLowerCase();
  return userChoice
}

function compChoice() {
  let compChoice = Math.random();
  if (compChoice < 0.34) {
    compChoice = "rock";
  } else if (compChoice <= 0.67) {
    compChoice = "paper";
  } else {
    compChoice = "scissors";
  }
  return compChoice
}

function playRound(userChoice, compChoice) {
  //Rock Choice
  if (userChoice == "rock" && compChoice == "scissors") {
    return "You Win! rock beats scissors!";
  } else if (userChoice == "rock" && compChoice == "paper") {
    return "Loser! paper Beats rock";
  } else if (userChoice == "rock" && compChoice == "rock") {
    return "It's a Draw";
  } else {
    return "Something Went Wrong";
  }
  //paper Choice
  if (userChoice == "paper" && compChoice == "rock") {
    return "You Win! paper beats rock";
  } else if (userChoice == "paper" && compChoice == "scissors") {
    return "You Lose! scissors beats paper";
  } else if (userChoice == "paper" && compChoice == "paper") {
    return "It's a Draw";
  } else {
    return "Something Went wrong";
  }
  //scissors Choice
  if (userChoice == "scissors" && compChoice == "paper") {
    return "You win! scissors beat paper";
  } else if (userChoice == "scissors" && compChoice == "rock") {
    return "You Lose! rock beats scissors";
  } else if (userChoice == "scissors" && compChoice == "scissors") {
    return "It's a Draw";
  } else {
    return "Something Went Wrong";
  }
}

console.log(playRound(userChoice(), compChoice()))

【问题讨论】：

第一个 else{return...} 跳过其余的流程。

标签： javascript function if-statement

【解决方案1】：

如果您不输入rock，则将执行第一个else 语句，因为if 或else if 条件都不为真。它将返回Something went wrong，而不对paper 或scissors 执行任何测试。

所有其他组合都应该是附加的else if 语句，并且您应该在最后只有一个else。

function userChoice() {
  const userChoice = prompt("Do you choose Rock, Paper, or Scissors?").toLowerCase();
  return userChoice
}

function compChoice() {
  let compChoice = Math.random();
  if (compChoice < 0.34) {
    compChoice = "rock";
  } else if (compChoice <= 0.67) {
    compChoice = "paper";
  } else {
    compChoice = "scissors";
  }
  return compChoice
}

function playRound(userChoice, compChoice) {
  //Rock Choice
  if (userChoice == "rock" && compChoice == "scissors") {
    return "You Win! rock beats scissors!";
  } else if (userChoice == "rock" && compChoice == "paper") {
    return "Loser! paper Beats rock";
  } else if (userChoice == "rock" && compChoice == "rock") {
    return "It's a Draw";
  }
  //paper Choice
  else if (userChoice == "paper" && compChoice == "rock") {
    return "You Win! paper beats rock";
  } else if (userChoice == "paper" && compChoice == "scissors") {
    return "You Lose! scissors beats paper";
  } else if (userChoice == "paper" && compChoice == "paper") {
    return "It's a Draw";
  }
  //scissors Choice
  else if (userChoice == "scissors" && compChoice == "paper") {
    return "You win! scissors beat paper";
  } else if (userChoice == "scissors" && compChoice == "rock") {
    return "You Lose! rock beats scissors";
  } else if (userChoice == "scissors" && compChoice == "scissors") {
    return "It's a Draw";
  } else {
    return "Something Went Wrong";
  }
}

console.log(playRound(userChoice(), compChoice()))

或者您可以使用嵌套的if 块。

function userChoice() {
  const userChoice = prompt("Do you choose Rock, Paper, or Scissors?").toLowerCase();
  return userChoice
}

function compChoice() {
  let compChoice = Math.random();
  if (compChoice < 0.34) {
    compChoice = "rock";
  } else if (compChoice <= 0.67) {
    compChoice = "paper";
  } else {
    compChoice = "scissors";
  }
  return compChoice
}

function playRound(userChoice, compChoice) {
  //Rock Choice
  if (userChoice == "rock") {
    if (compChoice == "scissors") {
      return "You Win! rock beats scissors!";
    } else if (compChoice == "paper") {
      return "Loser! paper Beats rock";
    } else if (compChoice == "rock") {
      return "It's a Draw";
    } else {
      return "Something Went Wrong";
    }
  }
  //paper Choice
  else if (userChoice == "paper") {
    if (compChoice == "rock") {
      return "You Win! paper beats rock";
    } else if (compChoice == "scissors") {
      return "You Lose! scissors beats paper";
    } else if (compChoice == "paper") {
      return "It's a Draw";
    } else {
      return "Something Went Wrong";
    }
  }
  //scissors Choice
  else if (userChoice == "scissors") {
    if (compChoice == "paper") {
      return "You win! scissors beat paper";
    } else if (userChoice == "scissors" && compChoice == "rock") {
      return "You Lose! rock beats scissors";
    } else if (userChoice == "scissors" && compChoice == "scissors") {
      return "It's a Draw";
    } else {
      return "Something Went Wrong";
    }
  } else {
    return "That's not a valid choice";
  }
}

console.log(playRound(userChoice(), compChoice()))

【讨论】：

哦哦，说得有道理！如此简单，但我看不到它。非常感谢，我已经花了好几个小时了！

【解决方案2】：

试试这个：您需要删除每个 if 语句末尾的返回，因为它们会无条件地发生。如果没有运行其他返回，您可以在最后返回以获得该结果。

function playRound(userChoice, compChoice) {
  //Rock Choice
  if (userChoice == "rock" && compChoice == "scissors") {
    return "You Win! rock beats scissors!";
  } else if (userChoice == "rock" && compChoice == "paper") {
    return "Loser! paper Beats rock";
  } else if (userChoice == "rock" && compChoice == "rock") {
    return "It's a Draw";
  }
  //paper Choice
  if (userChoice == "paper" && compChoice == "rock") {
    return "You Win! paper beats rock";
  } else if (userChoice == "paper" && compChoice == "scissors") {
    return "You Lose! scissors beats paper";
  } else if (userChoice == "paper" && compChoice == "paper") {
    return "It's a Draw";
  }
  //scissors Choice
  if (userChoice == "scissors" && compChoice == "paper") {
    return "You win! scissors beat paper";
  } else if (userChoice == "scissors" && compChoice == "rock") {
    return "You Lose! rock beats scissors";
  } else if (userChoice == "scissors" && compChoice == "scissors") {
    return "It's a Draw";
  }
  return "Something Went Wrong";
}

【讨论】：

【解决方案3】：

这是因为你的 playRound() 函数永远不会超过这个：

if (userChoice == "rock" && compChoice == "scissors") {
    return "You Win! rock beats scissors!";
} else if (userChoice == "rock" && compChoice == "paper") {
    return "Loser! paper Beats rock";
} else if (userChoice == "rock" && compChoice == "rock") {
    return "It's a Draw";
} else {
    return "Something Went Wrong";
}

这是由于您在该代码块末尾的 else 。由于userChoice 设置为纸或剪刀，因此它属于else 并且不会前进到函数的其余部分。您可以像这样链接 ifs 来修复：

if (userChoice == "rock" && compChoice == "scissors") {
    return "You Win! rock beats scissors!";
} else if (userChoice == "rock" && compChoice == "paper") {
    return "Loser! paper Beats rock";
} else if (userChoice == "rock" && compChoice == "rock") {
    return "It's a Draw";
} else if (userChoice == "paper" && compChoice == "rock") {
    return "You Win! paper beats rock";
} else if (userChoice == "paper" && compChoice == "scissors") {
    return "You Lose! scissors beats paper";
} else if (userChoice == "paper" && compChoice == "paper") {
    return "It's a Draw";
} .... 
rest of ifs 
....
else {
    return "Something Went wrong";
}

【讨论】：

谢谢！！你不知道我在这上面花了多少时间，很高兴它很容易解决！

【解决方案4】：

不要因提前返回而中断流程。

function userChoice() {
  const userChoice = prompt("Do you choose Rock, Paper, or Scissors?").toLowerCase();
  return userChoice
}

function compChoice() {
  let compChoice = Math.random();
  if (compChoice < 0.34) {
    compChoice = "rock";
  } else if (compChoice <= 0.67) {
    compChoice = "paper";
  } else {
    compChoice = "scissors";
  }
  return compChoice
}

function playRound(userChoice, compChoice) {
  //Rock Choice
  if (userChoice == "rock" && compChoice == "scissors") {
    return "You Win! rock beats scissors!";
  } else if (userChoice == "rock" && compChoice == "paper") {
    return "Loser! paper Beats rock";
  } else if (userChoice == "rock" && compChoice == "rock") {
    return "It's a Draw";
  } else
  //paper Choice
  if (userChoice == "paper" && compChoice == "rock") {
    return "You Win! paper beats rock";
  } else if (userChoice == "paper" && compChoice == "scissors") {
    return "You Lose! scissors beats paper";
  } else if (userChoice == "paper" && compChoice == "paper") {
    return "It's a Draw";
  } else
  //scissors Choice
  if (userChoice == "scissors" && compChoice == "paper") {
    return "You win! scissors beat paper";
  } else if (userChoice == "scissors" && compChoice == "rock") {
    return "You Lose! rock beats scissors";
  } else if (userChoice == "scissors" && compChoice == "scissors") {
    return "It's a Draw";
  } else {
    return "Something Went Wrong";
  }
}

console.log(playRound(userChoice(), compChoice()))

【讨论】：