64 lines
1.7 KiB
Markdown
64 lines
1.7 KiB
Markdown
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---
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id: 587d7b8d367417b2b2512b59
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title: Import a Default Export
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challengeType: 1
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videoUrl: ''
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localeTitle: 导入默认导出
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---
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## Description
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<section id="description">在上一次挑战中，您了解了<code>export default</code>及其用途。请务必注意，要导入默认导出，您需要使用不同的<code>import</code>语法。在下面的示例中，我们有一个函数<code>add</code> ，它是文件的默认导出<code>"math_functions"</code> 。以下是如何导入它： <blockquote>从“math_functions”导入添加; <br>添加（5,4）; //将返回9 </blockquote>语法在一个关键位置有所不同 - 导入的值<code>add</code>不会被花括号<code>{}</code>包围。与导出值不同，导入默认导出的主要方法是在<code>import</code>后简单地写入值的名称。 </section>
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## Instructions
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<section id="instructions">在下面的代码中，请从文件<code>"math_functions"</code>导入默认导出， <code>subtract</code> ，该文件位于与此文件相同的目录中。 </section>
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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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- text: 正确导入<code>export default</code>方法。
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testString: 'getUserInput => assert(getUserInput("index").match(/import\s+subtract\s+from\s+"math_functions"/g), "Properly imports <code>export default</code> method.");'
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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='js-seed'>
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```js
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"use strict";
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subtract(7,4);
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```
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</div>
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### Before Test
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<div id='js-setup'>
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```js
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window.require = function(str) {
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if (str === 'math_functions') {
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return function(a, b) {
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return a - b;
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}}};
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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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```js
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// solution required
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```
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</section>
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