65 lines
2.1 KiB
Markdown
65 lines
2.1 KiB
Markdown
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---
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id: 56592a60ddddeae28f7aa8e1
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title: Access Multi-Dimensional Arrays With Indexes
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challengeType: 1
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guideUrl: 'https://chinese.freecodecamp.org/guide/certificates/access-array-data-with-indexes'
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videoUrl: ''
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localeTitle: 访问带索引的多维数组
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---
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## Description
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<section id="description">考虑<dfn>多维</dfn>数组的一种方法是作为<em>数组的数组</em> 。使用括号访问数组时，第一组括号引用最外层（第一级）数组中的条目，另外一对括号引用内部的下一级条目。 <strong>例</strong> <blockquote> var arr = [ <br> [1,2,3]， <br> [4,5,6] <br> [7,8,9] <br> [[10,11,12]，13,14] <br> ]。 <br> ARR [3]; //等于[[10,11,12]，13,14] <br> ARR [3] [0]; //等于[10,11,12] <br> ARR [3] [0] [1]; //等于11 </blockquote> <strong>注意</strong> <br>数组名称和方括号之间不应该有任何空格，如<code>array [0][0]</code> ，甚至不允许使用此<code>array [0] [0]</code> 。尽管JavaScript能够正确处理，但这可能会让其他程序员在阅读代码时感到困惑。 </section>
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## Instructions
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<section id="instructions">使用括号表示法从<code>myArray</code>选择一个元素，使<code>myData</code>等于<code>8</code> 。 </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: <code>myData</code>应该等于<code>8</code> 。
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testString: 'assert(myData === 8, "<code>myData</code> should be equal to <code>8</code>.");'
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- text: 您应该使用括号表示法从<code>myArray</code>读取正确的值。
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testString: 'assert(/myArray\[2\]\[1\]/g.test(code) && !/myData\s*=\s*(?:.*[-+*/%]|\d)/g.test(code), "You should be using bracket notation to read the correct value from <code>myArray</code>.");'
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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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// Setup
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var myArray = [[1,2,3], [4,5,6], [7,8,9], [[10,11,12], 13, 14]];
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// Only change code below this line.
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var myData = myArray[0][0];
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```
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</div>
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### After Test
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<div id='js-teardown'>
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```js
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console.info('after the test');
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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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