如何防止猜数字游戏中的重复猜测？

Question

我创建了一个名为尝试收集用户猜到的数字的数组。当用户最终猜出正确的数字时，将尝试次数和猜中的数字告诉用户。我如何避免用户猜测他们已经猜到的数字？我知道每次猜测后我都必须检查数组，看看这个数字是否已经被猜到并且在数组中。 （如果guess 在数组中，显示消息“你已经猜到了，再试一次”）另外，我应该将该猜测添加到猜测数中还是不包括它，因为它是重复猜测？

let num = Math.floor(Math.random() * 20) + 1;

console.log(num);

let num_guess = 0
let tries = []

function do_guess() {
    let guess = Number(document.getElementById("guess").value);

    let message = document.getElementById("message");

    if (isNaN(guess)) {
        message.innerHTML = 'That is not a number!';
    }
    else if (guess > 20) {
        message.innerHTML = 'That number is not in range, try again.';
        num_guess++
        tries.push(guess)
    }
    else if (guess > num) {
        message.innerHTML = "No, try a lower number.";
        num_guess++
        tries.push(guess)
    }
    else if (guess < num) {
        message.innerHTML = "No, try a higher number.";
        num_guess++
        tries.push(guess)
    }
    else if (guess == num) {
        num_guess++
        tries.push(guess)
        message.innerHTML = "You got it! It took you " + num_guess + " tries and your guesses were " + tries + ".";
    }
}

Answer 1

简单，使用Array.includes：

[1, 2, 3].includes(1)
> true
[1, 2, 3].includes(4)
> false

关于是否要包含重复的猜测：由您决定。

Answer 2

您可以使用includes 来检查一个元素是否存在于数组中。

includes() 方法判断一个数组是否包含某个 其条目之间的值，根据需要返回 true 或 false。

你需要在所有条件之前添加以下代码

if (tries.includes(guess)) {
        message.innerHTML = "You guessed that already, try again";
    } 

let num = Math.floor(Math.random() * 20) + 1;

console.log(num);

let num_guess = 0;
let tries = [];
const guessContainer = document.getElementById("guess");
const check = document.getElementById("check");
let message = document.getElementById("message");

guessContainer.addEventListener("keyup", (e) => {
  message.innerHTML = "";
});

function do_guess() {
  let guess = Number(guessContainer.value);
  let isCorrect = false;

  if (tries.includes(guess)) {
    message.innerHTML = "You guessed that already, try again";
  } else if (isNaN(guess)) {
    message.innerHTML = "That is not a number!";
  } else if (guess > 20) {
    message.innerHTML = "That number is not in range, try again.";
    num_guess++;
    tries.push(guess);
  } else if (guess > num) {
    message.innerHTML = "No, try a lower number.";
    num_guess++;
    tries.push(guess);
  } else if (guess < num) {
    message.innerHTML = "No, try a higher number.";
    num_guess++;
    tries.push(guess);
  } else if (guess == num) {
    isCorrect = true;
    num_guess++;
    tries.push(guess);
    message.innerHTML =
      "You got it! It took you " +
      num_guess +
      " tries and your guesses were " +
      tries +
      ".";
  }
  if (isCorrect) {
    message.classList.add("right");
    message.classList.remove("wrong");
  } else {
    message.classList.add("wrong");
    message.classList.remove("right");
  }
}

check.addEventListener("click", do_guess);

body {
  padding: 1rem;
}

button {
  background-color: indianred;
  color: white;
  border: none;
  padding: .25rem .5rem;
  border-radius: 4px;
  text-transform: uppercase;
}

.wrong {
  color: tomato;
}

.right {
  color: green;
}

h5 {
  margin-top: 1rem;
}

<input type="text" id="guess" />
<button id="check">check</button>
<h5 id="message"></h5>

Answer 3

试试这个：

var num = Math.floor(Math.random() * 20) + 1;

console.log(num);

var num_guess = 0;
var tries = [];
function go_guess() {

  let guess = Number(document.getElementById("guess").value);
  
  let message = document.getElementById("message");
  if(tries.includes(guess)){
    message.innerText = "You guessed that already, try again";
  } else {
    
    if (isNaN(guess)) {
      message.innerHTML = 'That is not a number!';
    }
    else if (guess > 20) {
      message.innerHTML = 'That number is not in range, try again.';
      num_guess++;
      tries.push(guess);
    }
    else if (guess > num) {
      message.innerHTML = "No, try a lower number.";
      num_guess++;
      tries.push(guess);
    }
    else if (guess < num) {
      message.innerHTML = "No, try a higher number.";
      num_guess++;
      tries.push(guess);
    }
    else if (guess == num) {
      let _tries = `${tries[0]}`;
      for(let i = 1;i<tries.length;i++){
        _tries += `, ${tries[i]}`;
      }
      num_guess++;
      message.innerText = `You got it! It took you  ${num_guess} tries and your guesses were ${_tries}.`;
    }
  };
});