Javascript將類添加到除一個之外的多個元素-有解無憂

從 JavaScript 開始，我撰寫了一個小腳本，它在單擊時向元素添加一個類，然后當且僅當另一個元素是單擊時洗掉該類。

我試圖尊重 DRY，所以我知道我應該寫一個函式來避免重復代碼，例如：

function ToggleClass(element) {
  if (FacebookConst.classList.contains("link-ranking-active") || GoogleConst.classList.contains("link-ranking-active") || ComparisonConst.classList.contains("link-ranking-active") {
  //remove "link-ranking-active" class to all constants **BUT** of element    
  };  
};

但我不知道語法。

這是我的代碼：

const GoogleConst = document.getElementById('Google');
const FacebookConst = document.getElementById('Facebook');
const ComparisonConst = document.getElementById('Comparison');

const Page = document.getElementById("result");

GoogleConst.addEventListener("click", e => {
    GoogleConst.classList.add("link-ranking-active");
    if (FacebookConst.classList.contains("link-ranking-active") || ComparisonConst.classList.contains("link-ranking-active")) {
      FacebookConst.classList.remove("link-ranking-active");
      ComparisonConst.classList.remove("link-ranking-active");
    };
});

FacebookConst.addEventListener("click", e => {
    FacebookConst.classList.add("link-ranking-active");
    if (GoogleConst.classList.contains("link-ranking-active") || ComparisonConst.classList.contains("link-ranking-active")) {
      GoogleConst.classList.remove("link-ranking-active");
      ComparisonConst.classList.remove("link-ranking-active");
    };
});

ComparisonConst.addEventListener("click", e => {
    ComparisonConst.classList.add("link-ranking-active");
    if (FacebookConst.classList.contains("link-ranking-active") || GoogleConst.classList.contains("link-ranking-active")) {
      FacebookConst.classList.remove("link-ranking-active");
      GoogleConst.classList.remove("link-ranking-active");
    };
});

.link-ranking-active{
  box-sizing: border-box;
  position:relative;
  padding: 0.3em;
  height: 100%;
  width: 100%;
  border-radius: 0.3em;
  border: 0.15em solid #48ffd5;
}

<div class="page">
    <div class="ranking" id="ranking">
      <ul class="ul-menu">
        <li class="li-menu"><a class="link-ranking" id="Google" href="#key">Google</a></li>
        <li class="li-menu"><a class="link-ranking" id="Facebook" href="#key">Facebook</a></li>
        <li class="li-menu"><a class="link-ranking" id="Comparison" href="#key">Comparison</a></li>
      </ul>
    </div>
</div>

uj5u.com熱心網友回復：

此處使用的技術稱為事件委托。這是它的作業原理：

在容器上設定單個事件處理程式
如果不是錨標記，則忽略該事件
否則，清除所有錨點的類名
最后，將類名應用到事件的目標（被點擊的那個）。

const container = document.querySelector('.ul-menu');
const anchors = document.querySelectorAll('.ul-menu li a');

container.addEventListener('click', (e) => {
  if (e.target.nodeName !== "A") return;
  anchors.forEach(anchor => {
    anchor.classList.remove('link-ranking-active');
  });
  e.target.classList.add('link-ranking-active');

});

.link-ranking-active {
  box-sizing: border-box;
  position: relative;
  padding: 0.3em;
  height: 100%;
  width: 100%;
  border-radius: 0.3em;
  border: 0.15em solid #48ffd5;
}

<div class="page">
  <div class="ranking" id="ranking">
    <ul class="ul-menu">
      <li class="li-menu"><a class="link-ranking" id="Google" href="#key">Google</a></li>
      <li class="li-menu"><a class="link-ranking" id="Facebook" href="#key">Facebook</a></li>
      <li class="li-menu"><a class="link-ranking" id="Comparison" href="#key">Comparison</a></li>
    </ul>
  </div>
</div>

uj5u.com熱心網友回復：

很高興你意識到你應該清理它。一旦你看到它，代碼應該是相當不言自明的。

const elements = ['Google', 'Facebook', 'Comparison'].map(id => document.getElementById(id))

const eventHandler = (e => {
  elements.map(element => element.classList.remove("link-ranking-active"))
  e.target.classList.add("link-ranking-active")
})

elements.forEach(element => element.addEventListener("click", eventHandler))

.link-ranking-active {
  box-sizing: border-box;
  position: relative;
  padding: 0.3em;
  height: 100%;
  width: 100%;
  border-radius: 0.3em;
  border: 0.15em solid #48ffd5;
}

<div class="page">
  <div class="ranking" id="ranking">
    <ul class="ul-menu">
      <li class="li-menu"><a class="link-ranking" id="Google" href="#key">Google</a></li>
      <li class="li-menu"><a class="link-ranking" id="Facebook" href="#key">Facebook</a></li>
      <li class="li-menu"><a class="link-ranking" id="Comparison" href="#key">Comparison</a></li>
    </ul>
  </div>
</div>

uj5u.com熱心網友回復：

一個經典...

商品要知道 =
1- classList.toggle() 回傳一個布林值
2- classList.toggle( CLASSname, Force ) 使用強制設定類

document
 .querySelectorAll('a.link-ranking')
 .forEach((aLink,_,arr)=>{
  aLink.onclick =()=>{
    if ( aLink.classList.toggle('link-ranking-active')) {
      arr.forEach(a=>a.classList.toggle('link-ranking-active',aLink===a))
    }}
  })

.link-ranking-active {
  box-sizing    : border-box;
  position      : relative;
  padding       : 0.3em;
  height        : 100%;
  width         : 100%;
  border-radius : 0.3em;
  border        : 0.15em solid #48ffd5;
  }
ul.ul-menu li {
  margin : 1em ;
  }

<div class="page">
  <div class="ranking" id="ranking">
    <ul class="ul-menu">
      <li class="li-menu"><a class="link-ranking" id="Google" href="#key">Google</a></li>
      <li class="li-menu"><a class="link-ranking" id="Facebook" href="#key">Facebook</a></li>
      <li class="li-menu"><a class="link-ranking" id="Comparison" href="#key">Comparison</a></li>
    </ul>
  </div>
</div>

如果您不想在第二次單擊時洗掉該類：

document.querySelectorAll('a.link-ranking').forEach((aLink,_,arr)=>{
  aLink.onclick =()=>{
    arr.forEach(a=>a.classList.toggle('link-ranking-active',aLink===a))
  }})

.link-ranking-active {
  box-sizing    : border-box;
  position      : relative;
  padding       : 0.3em;
  height        : 100%;
  width         : 100%;
  border-radius : 0.3em;
  border        : 0.15em solid #48ffd5;
  }
ul.ul-menu li {
  margin : 1em ;
  }

<div class="page">
  <div class="ranking" id="ranking">
    <ul class="ul-menu">
      <li class="li-menu"><a class="link-ranking" id="Google" href="#key">Google</a></li>
      <li class="li-menu"><a class="link-ranking" id="Facebook" href="#key">Facebook</a></li>
      <li class="li-menu"><a class="link-ranking" id="Comparison" href="#key">Comparison</a></li>
    </ul>
  </div>
</div>

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標籤：javascript html css 功能班级

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