83 lines
2.0 KiB
Markdown
83 lines
2.0 KiB
Markdown
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---
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id: 56533eb9ac21ba0edf2244cd
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title: Accessing Nested Arrays
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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: 访问嵌套数组
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---
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## Description
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<section id="description">正如我们在前面的示例中所看到的，对象可以包含嵌套对象和嵌套数组。与访问嵌套对象类似，可以链接数组括号表示法来访问嵌套数组。以下是如何访问嵌套数组的示例： <blockquote> var ourPets = [ <br> { <br> animalType：“猫”， <br>名称：[ <br> “Meowzer” <br> “蓬松”， <br> “洁猫” <br> ] <br> }， <br> { <br>动物类型：“狗”， <br>名称：[ <br> “点”， <br> “库巴” <br> “羊羊” <br> ] <br> } <br> ]。 <br> ourPets [0] .names [1]; //“蓬松” <br> ourPets [1] .names [0]; //“Spot” </blockquote></section>
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## Instructions
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<section id="instructions">使用对象点和数组括号表示法从变量<code>myPlants</code>检索第二个树。 </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>secondTree</code>应该等于“松树”
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testString: 'assert(secondTree === "pine", "<code>secondTree</code> should equal "pine"");'
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- text: 使用点和括号表示法访问<code>myPlants</code>
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testString: 'assert(/=\s*myPlants\[1\].list\[1\]/.test(code), "Use dot and bracket notation to access <code>myPlants</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 myPlants = [
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{
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type: "flowers",
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list: [
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"rose",
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"tulip",
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"dandelion"
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]
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},
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{
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type: "trees",
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list: [
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"fir",
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"pine",
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"birch"
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]
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}
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];
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// Only change code below this line
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var secondTree = ""; // Change this line
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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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