101 lines
2.5 KiB
Markdown
101 lines
2.5 KiB
Markdown
---
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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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---
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## Description
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<section id='description'>
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We can also generate an array which contains all the keys stored in an object using the <code>Object.keys()</code> method and passing in an object as the argument. This will return an array with strings representing each property in the object. Again, there will be no specific order to the entries in the array.
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</section>
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## Instructions
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<section id='instructions'>
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Finish writing the <code>getArrayOfUsers</code> function so that it returns an array containing all the properties in the object it receives as an argument.
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</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: 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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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: The <code>getArrayOfUsers</code> function returns an array which contains all the keys in the <code>users</code> object
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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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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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return Object.keys(users);
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}
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console.log(getArrayOfUsers(users));
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```
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</section>
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