2018-10-10 22:03:03 +00:00
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---
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id: 587d7fa6367417b2b2512bc3
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2021-03-09 15:51:59 +00:00
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title: 用 D3 选择一组元素
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2018-10-10 22:03:03 +00:00
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challengeType: 6
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2020-09-17 16:13:05 +00:00
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forumTopicId: 301490
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2021-01-13 02:31:00 +00:00
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dashedName: select-a-group-of-elements-with-d3
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2018-10-10 22:03:03 +00:00
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---
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2020-12-16 07:37:30 +00:00
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# --description--
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2018-10-10 22:03:03 +00:00
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2021-03-09 15:51:59 +00:00
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`selectAll()` 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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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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`const anchors = d3.selectAll("a");`
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2018-10-10 22:03:03 +00:00
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2021-03-09 15:51:59 +00:00
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像 `select()` 方法一样，`selectAll()` 也支持链式调用，你可以在它之后调用其他方法。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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# --instructions--
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2018-10-10 22:03:03 +00:00
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2021-03-09 15:51:59 +00:00
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选择所有的 `li` 标签，通过 `.text()` 方法将它们的文本改为 `list item`。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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# --hints--
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2018-10-10 22:03:03 +00:00
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2021-03-09 15:51:59 +00:00
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页面上应该有 3 个 `li` 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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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert(
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$('li')
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.text()
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.match(/list item/g).length == 3
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);
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2018-10-10 22:03:03 +00:00
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```
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2021-03-09 15:51:59 +00:00
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应该能访问 `d3` 的对象。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert(code.match(/d3/g));
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```
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2018-10-10 22:03:03 +00:00
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2021-03-09 15:51:59 +00:00
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应该使用 `selectAll` 方法。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert(code.match(/\.selectAll/g));
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2018-10-10 22:03:03 +00:00
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```
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2020-08-13 15:24:35 +00:00
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2021-01-13 02:31:00 +00:00
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# --seed--
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## --seed-contents--
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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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// Add your code below this line
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// Add your code above this line
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</script>
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</body>
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```
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2020-12-16 07:37:30 +00:00
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# --solutions--
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2021-01-13 02:31:00 +00:00
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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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```
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