77 lines
2.2 KiB
Markdown
77 lines
2.2 KiB
Markdown
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---
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id: 587d7b7d367417b2b2512b1e
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title: Generate an Array of All Object Keys with Object.keys()
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challengeType: 1
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videoUrl: ''
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localeTitle: 使用Object.keys（）生成所有对象键的数组
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---
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## Description
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<section id="description">我们还可以使用<code>Object.keys()</code>方法生成一个数组，其中包含存储在对象中的所有键，并传入一个对象作为参数。这将返回一个数组，其中的字符串表示对象中的每个属性。同样，数组中的条目没有特定的顺序。 </section>
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## Instructions
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<section id="instructions">完成编写<code>getArrayOfUsers</code>函数，以便它返回一个数组，该数组包含它作为参数接收的对象中的所有属性。 </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>users</code>对象仅包含<code>Alan</code> ， <code>Jeff</code> ， <code>Sarah</code>和<code>Ryan</code>
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testString: 'assert("Alan" in users && "Jeff" in users && "Sarah" in users && "Ryan" in users && Object.keys(users).length === 4, "The <code>users</code> object only contains the keys <code>Alan</code>, <code>Jeff</code>, <code>Sarah</code>, and <code>Ryan</code>");'
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- text: <code>getArrayOfUsers</code>函数返回一个数组，其中包含<code>users</code>对象中的所有键
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testString: 'assert((function() { users.Sam = {}; users.Lewis = {}; let R = getArrayOfUsers(users); return (R.indexOf("Alan") !== -1 && R.indexOf("Jeff") !== -1 && R.indexOf("Sarah") !== -1 && R.indexOf("Ryan") !== -1 && R.indexOf("Sam") !== -1 && R.indexOf("Lewis") !== -1); })() === true, "The <code>getArrayOfUsers</code> function returns an array which contains all the keys in the <code>users</code> object");'
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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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let users = {
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Alan: {
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age: 27,
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online: false
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},
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Jeff: {
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age: 32,
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online: true
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},
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Sarah: {
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age: 48,
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online: false
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},
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Ryan: {
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age: 19,
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online: true
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}
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};
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function getArrayOfUsers(obj) {
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// change code below this line
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// change code above this line
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}
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console.log(getArrayOfUsers(users));
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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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