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javascript - 选中/取消选中所有按钮有什么问题？

转载 作者：行者123 更新时间：2023-12-02 21:07:35 28 4
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我正在学习 Wes Bos 30 天 Javascript 类(class)，在一项可选功能上，我需要在底部添加三个按钮:清除全部、选中全部和取消选中全部。这是代码

  <!DOCTYPE html>
    <html lang="en">
    <head>
      <meta charset="UTF-8">
      <title>LocalStorage</title>
      <link rel="stylesheet" href="style.css">
    </head>
    <body>
      <!--
          Fish SVG Cred:
          https://thenounproject.com/search/?q=fish&i=589236
       -->

       <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" x="0px" y="0px" viewBox="0 0 512 512" enable-background="new 0 0 512 512" xml:space="preserve"><g><path d="M495.9,425.3H16.1c-5.2,0-10.1,2.9-12.5,7.6c-2.4,4.7-2.1,10.3,0.9,14.6l39,56.4c2.6,3.8,7,6.1,11.6,6.1h401.7   c4.6,0,9-2.3,11.6-6.1l39-56.4c3-4.3,3.3-9.9,0.9-14.6C506,428.2,501.1,425.3,495.9,425.3z M449.4,481.8H62.6L43,453.6H469   L449.4,481.8z"/><path d="M158.3,122c7.8,0,14.1-6.3,14.1-14.1V43.4c0-7.8-6.3-14.1-14.1-14.1c-7.8,0-14.1,6.3-14.1,14.1v64.5   C144.2,115.7,150.5,122,158.3,122z"/><path d="M245.1,94.7c7.8,0,14.1-6.3,14.1-14.1V16.1c0-7.8-6.3-14.1-14.1-14.1C237.3,2,231,8.3,231,16.1v64.5   C231,88.4,237.3,94.7,245.1,94.7z"/><path d="M331.9,122c7.8,0,14.1-6.3,14.1-14.1V43.4c0-7.8-6.3-14.1-14.1-14.1s-14.1,6.3-14.1,14.1v64.5   C317.8,115.7,324.1,122,331.9,122z"/><path d="M9.6,385.2c5.3,2.8,11.8,1.9,16.2-2.2l50.6-47.7c56.7,46.5,126.6,71.9,198.3,71.9c0,0,0,0,0,0   c87.5,0,169.7-36.6,231.4-103.2c5-5.4,5-13.8,0-19.2c-61.8-66.5-144-103.2-231.4-103.2c-72,0-142.2,25.6-199,72.5l-50-47.1   c-4.4-4.1-10.9-5-16.2-2.2c-5.3,2.8-8.3,8.7-7.4,14.6l11.6,75L2.2,370.6C1.3,376.5,4.2,382.4,9.6,385.2z M380.9,230.8   c34.9,14.3,67.2,35.7,95.3,63.6c-10.1,10-20.8,19.2-31.9,27.5c-22.4-3.3-29.6-8.8-30.7-9.7c-4-5.7-11.8-7.7-18.1-4.4   c-6.9,3.6-9.5,12.2-5.9,19.1c1.9,3.5,7.3,10.3,22.4,16c-10.1,5.7-20.5,10.7-31.1,15.1C352.4,320.2,352.4,268.6,380.9,230.8z    M36.3,255.6l29.4,27.7c5.3,5,13.6,5.1,19.1,0.3c53.2-47.6,120.7-73.7,190-73.7c26.9,0,53.2,3.9,78.5,11.3   c-29.3,44.6-29.3,102,0,146.6c-25.3,7.4-51.6,11.3-78.5,11.3c-69,0-136.3-26-189.4-73.2c-2.7-2.4-13.4-6.3-19.1,0.3l-30.1,28.3   l5.7-40C42.2,293,36.3,255.6,36.3,255.6z"/><circle cx="398.8" cy="273.8" r="14.1"/></g></svg>

      <div class="wrapper">
        <h2>LOCAL TAPAS</h2>
        <p></p>
        <ul class="plates">
          <li>Loading Tapas...</li>
        </ul>
        <form class="add-items">
          <input type="text" name="item" placeholder="Item Name" required>
          <input type="submit" value="+ Add Item">
          <hr />
          <button type="button" name="clearAll">Clear all</button>
          <button type="button" name="checkThemAll">Check all</button>
          <button type="button" name="uncheckThemAll">Uncheck all</button>


        </form>
      </div>

    <script>
      const addItems = document.querySelector('.add-items');
      const itemsList = document.querySelector('.plates');
      const items = JSON.parse(localStorage.getItem('items')) || [];
      const buttons = document.querySelectorAll('[type=button]')

      function addItem(e) {
        e.preventDefault();
        const text = (this.querySelector('[name=item]')).value
        const item = {
          text,
          done: false
        }
        items.push(item);
        populateList(items, itemsList)
        this.reset();
        localStorage.setItem('items', JSON.stringify(items))
      }

      function populateList(plates = [], platesList){

        platesList.innerHTML = plates.map((plate, i) => {
          return `
          <li>
            <input type="checkbox" data-index=${i} id="item${i}" ${plate.done ? 'checked' : null} />
            <label for="item${i}">${plate.text}</label>  
          </li>
          `
        }).join('');
      }

      function toggleDone(e){
        if (!e.target.matches('input')) return; 
        const el = e.target;
        const index = el.dataset.index;
        items[index].done = !items[index].done;
        localStorage.setItem('items', JSON.stringify(items));
        populateList(items, itemsList);
      }

      function clearOptions() {
        if (this.name === "clearAll"){
          localStorage.removeItem('items');
          items.splice(0, items.length)

        } else if( this.name === "checkThemAll"){
          items.map(item => {
            item.done = "true";
          })
          localStorage.setItem('items', JSON.stringify(items));

        } else if (this.name === "uncheckThemAll"){
          items.map(item => {
            item.done = "false";
          })
          localStorage.setItem('items', JSON.stringify(items));
        } else return;

        populateList(items, itemsList)
        console.table("ITEMS", items)
        console.table("LOCALSTORAGE", localStorage)
      }

      addItems.addEventListener('submit', addItem);
      itemsList.addEventListener('click', toggleDone);
      buttons.forEach(button => button.addEventListener('click', clearOptions));

      populateList(items, itemsList);
    </script>


    </body>
    </html>

如果有人能告诉我为什么我的 checkAll 和 uncheckAll 按钮无法正常工作，我将不胜感激。他们都检查所有，但不会取消任何检查。当我 console.log 时，项目和本地存储似乎工作正常。

谢谢!

最佳答案

您使用的是字符串，而不是 bool 值:

item.done = "false"

应该是:

item.done = false

在这里查看它的工作情况:https://jsfiddle.net/0j5m91p4/

因为您使用的是字符串，所以它是一个真值，因此它将计算为 true。

关于javascript - 选中/取消选中所有按钮有什么问题？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/61186737/

28 4 0
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