在 Javascript 中，我如何編寫一個 function 會影響多個按鈕，每個按鈕都有自己單獨的 arrays？

Question

我目前正在使用三個單獨的按鈕設置一個應用程序，每個按鈕都應該隨機 select 一個特定於該按鈕的數組中的元素。 我已經成功地為每個按鈕編寫了單獨的功能，但我想知道是否有辦法將它壓縮成一個可以應用於所有三個按鈕的 function。

這是我目前的 Javascript：

const greyButton = document.querySelector('#grey');
greyButton.addEventListener('click', () => {
  let grey = ['Statblocks/Grey/badger.png', 'Statblocks/Grey/giantrat.png', 'Statblocks/Grey/badger.png', 'Statblocks/Grey/boar.png', 'Statblocks/Grey/panther.png', 'Statblocks/Grey/gitant badger.png', 'Statblocks/Grey/dire wolf.png', 'Statblocks/Grey/giant elk.png']
  
  for (i=0;i<grey.length;i++){
    let greyBalls = grey[Math.floor(Math.random() * grey.length)];
    document.getElementById('greyBall').src = greyBalls;
  }
});

const rustButton = document.querySelector('#rust');
rustButton.addEventListener('click', () => {
  let rust = ['Statblocks/Rust/rat.png', 'Statblocks/Rust/owl.png', 'Statblocks/Rust/mastiff.png', 'Statblocks/Rust/goat.png', 'Statblocks/Rust/giant goat.png', 'Statblocks/Rust/giant boar.png', 'Statblocks/Rust/lion.png', 'Statblocks/Rust/brown bear.png']
  
  for (i=0;i<rust.length;i++){
    let rustBalls = rust[Math.floor(Math.random() * rust.length)];
    document.getElementById('rustBall').src = rustBalls;
  }
});

const tanButton = document.querySelector('#tan');
tanButton.addEventListener('click', () => {
  let tan = ['Statblocks/Tan/jackal.png', 'Statblocks/Tan/ape.png', 'Statblocks/Tan/baboon.png', 'Statblocks/Tan/axe beak.png', 'Statblocks/Tan/black bear.png', 'Statblocks/Tan/giant weasel.png', 'Statblocks/Tan/giant hyena.png', 'Statblocks/Tan/tiger.png']
  
  for (i=0;i<tan.length;i++){
    let tanBalls = tan[Math.floor(Math.random() * tan.length)];
    document.getElementById('tanBall').src = tanBalls;
  }
});

和連接的HTML：

 <div class="row">
            <div class="column">
                <h1>Grey Bag of Tricks</h1>
                <button class="button" id='grey'>Draw from the Bag</button>
                <img src="" alt="" id="greyBall">
            </div>
            <div class="column">
                <h1>Rust Bag of Tricks</h1>
                <button class="button" id='rust'>Draw from the Bag</button>
                <img src="" alt="" id="rustBall">
            </div>
            <div class="column">
                <h1>Tan Bag of Tricks</h1>
                <button class="button" id='tan'>Draw from the Bag</button>
                <img src="" alt="" id="tanBall">
            </div>
        </div>

Answer 1

 var urlsByColor = { grey: ['Statblocks/Grey/badger.png', 'Statblocks/Grey/giantrat.png', 'Statblocks/Grey/badger.png', 'Statblocks/Grey/boar.png', 'Statblocks/Grey/panther.png', 'Statblocks/Grey/gitant badger.png', 'Statblocks/Grey/dire wolf.png', 'Statblocks/Grey/giant elk.png'], rust: ['Statblocks/Rust/rat.png', 'Statblocks/Rust/owl.png', 'Statblocks/Rust/mastiff.png', 'Statblocks/Rust/goat.png', 'Statblocks/Rust/giant goat.png', 'Statblocks/Rust/giant boar.png', 'Statblocks/Rust/lion.png', 'Statblocks/Rust/brown bear.png'], tan: ['Statblocks/Tan/jackal.png', 'Statblocks/Tan/ape.png', 'Statblocks/Tan/baboon.png', 'Statblocks/Tan/axe beak.png', 'Statblocks/Tan/black bear.png', 'Statblocks/Tan/giant weasel.png', 'Statblocks/Tan/giant hyena.png', 'Statblocks/Tan/tiger.png'] }; function changeBall (e) { const urls = urlsByColor[e.target.id]; const randomIndex = Math.floor(Math.random() * urls.length); const randomUrl = urls[randomIndex]; const associatedBall = e.target.closest('.column').querySelector('.ball'); console.log(`change ${e.target.id} to ${randomUrl}`); associatedBall.src = randomUrl; console.log(associatedBall); } [...document.querySelectorAll('.color.button')].forEach(button => button.addEventListener('click', changeBall) );

 <div class="row"> <div class="column"> <h1>Grey Bag of Tricks</h1> <button class="button color" id='grey'>Draw from the Bag</button> <img src="" alt="" class="ball" id="greyBall"> </div> <div class="column"> <h1>Rust Bag of Tricks</h1> <button class="button color" id='rust'>Draw from the Bag</button> <img src="" alt="" class="ball" id="rustBall"> </div> <div class="column"> <h1>Tan Bag of Tricks</h1> <button class="button color" id='tan'>Draw from the Bag</button> <img src="" alt="" class="ball" id="tanBall"> </div> </div>

好的，所以有些事情發生了變化。

• 我將 url 列表提取到 map，它可以使用按鈕的 id 來查找要使用的 url
• 按鈕和球的標記更改為具有查找和查找的通用類
• 當點擊發生時，我們通過按鈕 id 獲取 url
• 然后我們得到一個像以前一樣的隨機索引
• 我們得到該索引的隨機關聯 url
• 我們通過父列 class 在上下文中找到與按鈕關聯的球
• 最后我們改變球的 url

Answer 2

通常，您將相似的重復部分放在 function 中，然后通過將其替換為 function 的參數來抽象出每種用法中不同的所有部分：

function addHandler(buttonSelector, ballImages, ballId) {
  const button = document.querySelector(buttonSelector);
  button.addEventListener('click', e => {
    for (let i=0; i<ballImages.length; i++) {
      let ball = ballImages[Math.floor(Math.random() * ballImages.length)];
      document.getElementById(ballId).src = ball;
    }
  });
}

這樣你就可以這樣稱呼它

addHandler('#grey', ['Statblocks/Grey/badger.png', 'Statblocks/Grey/giantrat.png', 'Statblocks/Grey/badger.png', 'Statblocks/Grey/boar.png', 'Statblocks/Grey/panther.png', 'Statblocks/Grey/gitant badger.png', 'Statblocks/Grey/dire wolf.png', 'Statblocks/Grey/giant elk.png'], 'greyBall');
addHandler('#rust', ['Statblocks/Rust/rat.png', 'Statblocks/Rust/owl.png', 'Statblocks/Rust/mastiff.png', 'Statblocks/Rust/goat.png', 'Statblocks/Rust/giant goat.png', 'Statblocks/Rust/giant boar.png', 'Statblocks/Rust/lion.png', 'Statblocks/Rust/brown bear.png'], 'rustBall');
addHandler('#tan', ['Statblocks/Tan/jackal.png', 'Statblocks/Tan/ape.png', 'Statblocks/Tan/baboon.png', 'Statblocks/Tan/axe beak.png', 'Statblocks/Tan/black bear.png', 'Statblocks/Tan/giant weasel.png', 'Statblocks/Tan/giant hyena.png', 'Statblocks/Tan/tiger.png'], 'tanBall');

不過，這仍然是一些重復。 我們可以通過對數據進行額外處理來避免這種情況，以便我們可以傳遞更簡單的值：

function addHandler(id, imageNames) {
  const buttonSelector = '#' + id;
  const ballImages = imageNames.map(name => `Statblocks/${id[0].toUpperCase()+id.slice(1)}/${name}.png}`);
  const ballId = id + 'Ball';

  … // rest as before
}

addHandler('grey', ['badger', 'giantrat', 'badger', 'boar', 'panther', 'gitant badger', 'dire wolf', 'giant elk']);
addHandler('rust', ['rat', 'owl', 'mastiff', 'goat', 'giant goat', 'giant boar', 'lion', 'brown bear']);
addHandler('tan', ['jackal', 'ape', 'baboon', 'axe beak', 'black bear', 'giant weasel', 'giant hyena', 'tiger']);

最后，我將querySelector更改為getElementById查找，並刪除不必要的循環，我們到達

function addHandler(id, imageNames) {
  const ballImages = imageNames.map(name => `Statblocks/${id[0].toUpperCase()+id.slice(1)}/${name}.png}`);
  const button = document.getElementById(id);
  button.addEventListener('click', e => {
    let ball = ballImages[Math.floor(Math.random() * ballImages.length)];
    document.getElementById(id + 'Ball').src = ball;
  });
}

addHandler('grey', ['badger', 'giantrat', 'badger', 'boar', 'panther', 'gitant badger', 'dire wolf', 'giant elk']);
addHandler('rust', ['rat', 'owl', 'mastiff', 'goat', 'giant goat', 'giant boar', 'lion', 'brown bear']);
addHandler('tan', ['jackal', 'ape', 'baboon', 'axe beak', 'black bear', 'giant weasel', 'giant hyena', 'tiger']);