如何在单击 javascript 后添加 CSS 并在未单击时将其删除

Question

我遇到了一个问题 javascript 点击更改 CSS

希望点击的选项的外框和文字点击后可以加粗，但是没有选中的不要加粗，试过好几种写法，还是不知道怎么完成这个要求，希望能得到大家的帮助。 谢谢你

 let plan = document.querySelector('.plan'); let price = document.querySelector('.price'); let item = document.querySelectorAll('.item'); for (var i = 0; i < item.length; i++) { item[i].addEventListener('click', showplan, false); } function showplan(e) { //Originally intended to increase this way, but it seems that it can't be written like this // e.target.closesst('li').classList.add('bold') // e.target.closesst('h2').classList.add('bold') const planSelected = e.target.closest('li').querySelector('h2'); const priceSelected = e.target.closest('li').querySelector('p'); plan.textContent = planSelected.textContent; price.textContent = priceSelected.textContent; }

 @charset "UTF-8";.product＿list { display: flex; }.product＿list.item { border: 1px solid #ccc; border-radius: 6px; text-align: center; padding: 20px; margin: 20px; }.product＿list.item h2 { margin-bottom: 16px; }.product＿list.item:hover { border: 1px solid #222; }.show { border: 2px solid blue; padding: 20px; }.bold { border: 3px solid; font-weight: 900; }

 <ul class="product＿list"> <li class="item"> <h2>coke</h2> <p>$100</p> </li> <li class="item"> <h2>beef</h2> <p>$600</p> </li> </ul> <h2 class="show">Your food of choice is <span class="plan"></span>The total price is<span class="price"></span></h2>

Answer 1

如何在点击 javascript 后添加 CSS 并在未点击时将其删除？

假设我们有一个类“item”，我们想改变“h1”

add class:
e.currentTarget.classList.add('item')

remove class:
e.currentTarget.classList.remove('item')

toggle class:
e.currentTarget.classList.toggle('item')

切换意味着：（如果 h1 有这个 class，删除，如果没有，添加）

Answer 2

您需要切换 class，您可以通过从每个项目中删除它并仅将其设置为选定的项目来做到这一点：

item.forEach(el => el.classList.remove('active'))
e.currentTarget.classList.add('active')

您还有一个 CSS 特异性问题：

仅使用.bold时， border将被.product＿list.item覆盖

注意，尝试使用currentTarget

 const plan = document.querySelector('.plan'); const price = document.querySelector('.price'); const item = document.querySelectorAll('.item'); function showplan(e) { const target = e.currentTarget; const closestLi = target.closest('li'); const planSelected = closestLi.querySelector('h2'); const priceSelected = closestLi.querySelector('p'); item.forEach(el => el.classList.remove('active')) target.classList.add('active') plan.textContent = planSelected.textContent; price.textContent = priceSelected.textContent; } item.forEach(el => el.addEventListener('click', showplan));

 @charset "UTF-8";.product＿list { display: flex; }.product＿list.item { border: 1px solid #ccc; border-radius: 6px; text-align: center; padding: 20px; margin: 20px; }.product＿list.item h2 { margin-bottom: 16px; }.product＿list.item:hover, { border: 1px solid #222; }.product＿list.active { border: 3px solid red; font-weight: 900; color: red; }.show { border: 2px solid blue; padding: 20px; }

 <ul class="product＿list"> <li class="item"> <h2>coke</h2> <p>$100</p> </li> <li class="item"> <h2>beef</h2> <p>$600</p> </li> </ul> <h2 class="show">Your food of choice is <span class="plan"></span>The total price is<span class="price"></span></h2>

Answer 3

使用 jQuery，两个:radio及其对应的label ：

 var $plan = $('.plan'); var $price = $('.price'); var $item = $('.item'); $('.item').on('click', showplan); function showplan(e) { const plan = $(this).find('h2').text(); const price = $(this).find('p').text(); $plan.text(plan); $price.text(price); }

 @charset "UTF-8";.product＿list { display: flex; }.product＿list.item { border: 1px solid #ccc; border-radius: 6px; text-align: center; padding: 20px; margin: 20px; cursor: pointer; }.product＿list input { display: none; }.product＿list.item h2 { margin-bottom: 16px; }.product＿list.item:hover { border: 1px solid #222; }.show { border: 2px solid blue; padding: 20px; }.product＿list input:checked + label { outline: 2px solid black; /* Prevent jumping. */ border: 1px solid black; font-weight: 900; }

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <div class="product＿list"> <input type="radio" name="product" id="coke"> <label class="item" for="coke"> <h2>coke</h2> <p>$100</p> </label> <input type="radio" name="product" id="beef"> <label class="item" for="beef"> <h2>beef</h2> <p>$600</p> </label> </div> <h2 class="show">Your food of choice is <span class="plan">?</span>. The total price is <span class="price">?</span>.</h2>