76 lines
2.2 KiB
Markdown
76 lines
2.2 KiB
Markdown
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---
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id: 56bbb991ad1ed5201cd392ca
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title: Access Array Data with Indexes
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challengeType: 1
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guideUrl: 'https://guide.freecodecamp.org/certificates/access-array-data-with-indexes'
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---
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## Description
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<section id='description'>
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We can access the data inside arrays using <code>indexes</code>.
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Array indexes are written in the same bracket notation that strings use, except that instead of specifying a character, they are specifying an entry in the array. Like strings, arrays use <dfn>zero-based</dfn> indexing, so the first element in an array is element <code>0</code>.
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<strong>Example</strong>
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<blockquote>var array = [50,60,70];<br>array[0]; // equals 50<br>var data = array[1]; // equals 60</blockquote>
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<strong>Note</strong><br>There shouldn't be any spaces between the array name and the square brackets, like <code>array [0]</code>. Although JavaScript is able to process this correctly, this may confuse other programmers reading your code.
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</section>
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## Instructions
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<section id='instructions'>
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Create a variable called <code>myData</code> and set it to equal the first value of <code>myArray</code> using bracket notation.
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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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- text: The variable <code>myData</code> should equal the first value of <code>myArray</code>.
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testString: 'assert((function(){if(typeof myArray !== "undefined" && typeof myData !== "undefined" && myArray[0] === myData){return true;}else{return false;}})(), "The variable <code>myData</code> should equal the first value of <code>myArray</code>.");'
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- text: The data in variable <code>myArray</code> should be accessed using bracket notation.
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testString: 'assert((function(){if(code.match(/\s*=\s*myArray\[0\]/g)){return true;}else{return false;}})(), "The data in variable <code>myArray</code> should be accessed using bracket notation.");'
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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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// Example
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var ourArray = [50,60,70];
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var ourData = ourArray[0]; // equals 50
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// Setup
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var myArray = [50,60,70];
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// Only change code below 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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var myArray = [50,60,70];
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var myData = myArray[0];
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```
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</section>
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