2018-10-10 18:03:03 -04:00
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---
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id: 587d7fa6367417b2b2512bc3
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challengeType: 6
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2020-09-18 00:13:05 +08:00
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forumTopicId: 301490
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2020-10-01 17:54:21 +02:00
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title: 用 D3 选择一组元素
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2018-10-10 18:03:03 -04:00
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---
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## Description
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2020-09-18 00:13:05 +08:00
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<section id='description'>
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<code>selectAll()</code> 方法选择一组元素。它以 HTML 节点数组的形式返回该文本中所有匹配所输入字符串的对象。以下是一个选择文本中所有锚标签的例子：
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<code>const anchors = d3.selectAll("a");</code>
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像 <code>select()</code> 方法一样，<code>selectAll()</code> 也支持链式调用，你可以在它之后调用其他方法。
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</section>
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2018-10-10 18:03:03 -04:00
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## Instructions
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2020-09-18 00:13:05 +08:00
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<section id='instructions'>
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选择所有的 <code>li</code> 标签，通过 <code>.text()</code> 方法将它的文本改为 "list item" 。
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</section>
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2018-10-10 18:03:03 -04:00
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## Tests
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<section id='tests'>
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```yml
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tests:
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2020-09-18 00:13:05 +08:00
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- text: "页面上应该有 3 个 <code>li</code> 元素，每个元素的文本内容应为 'list item'。大小写和空格必须一致。"
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2020-02-18 01:40:55 +09:00
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testString: assert($('li').text().match(/list item/g).length == 3);
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2020-09-18 00:13:05 +08:00
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- text: 你应该能访问 <code>d3</code> 的对象。
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2020-02-18 01:40:55 +09:00
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testString: assert(code.match(/d3/g));
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2020-09-18 00:13:05 +08:00
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- text: 你应该使用 <code>selectAll</code> 方法。
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2020-02-18 01:40:55 +09:00
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testString: assert(code.match(/\.selectAll/g));
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2018-10-10 18:03:03 -04:00
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='html-seed'>
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```html
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<body>
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<ul>
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<li>Example</li>
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<li>Example</li>
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<li>Example</li>
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</ul>
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<script>
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2020-09-18 00:13:05 +08:00
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// 在下面添加你的代码
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2018-10-10 18:03:03 -04:00
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2020-09-18 00:13:05 +08:00
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// 在上面添加你的代码
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2018-10-10 18:03:03 -04:00
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</script>
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</body>
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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2020-09-18 00:13:05 +08:00
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```html
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<body>
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<ul>
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<li>Example</li>
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<li>Example</li>
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<li>Example</li>
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</ul>
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<script>
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d3.selectAll("li")
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.text("list item")
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</script>
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</body>
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2018-10-10 18:03:03 -04:00
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```
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2020-08-13 17:24:35 +02:00
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2020-09-18 00:13:05 +08:00
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</section>
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