62 lines
3.4 KiB
Markdown
62 lines
3.4 KiB
Markdown
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---
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id: 587d7b7e367417b2b2512b20
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title: Use an Array to Store a Collection of Data
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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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The below is an example of the simplest implementation of an array data structure. This is known as a <dfn>one-dimensional array</dfn>, meaning it only has one level, or that it does not have any other arrays nested within it. Notice it contains <dfn>booleans</dfn>, <dfn>strings</dfn>, and <dfn>numbers</dfn>, among other valid JavaScript data types:
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<blockquote>let simpleArray = ['one', 2, 'three’, true, false, undefined, null];<br>console.log(simpleArray.length);<br>// logs 7</blockquote>
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All array's have a length property, which as shown above, can be very easily accessed with the syntax <code>Array.length</code>.
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A more complex implementation of an array can be seen below. This is known as a <dfn>multi-dimensional array</dfn>, or an array that contains other arrays. Notice that this array also contains JavaScript <dfn>objects</dfn>, which we will examine very closely in our next section, but for now, all you need to know is that arrays are also capable of storing complex objects.
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<blockquote>let complexArray = [<br> [<br> {<br> one: 1,<br> two: 2<br> },<br> {<br> three: 3,<br> four: 4<br> }<br> ],<br> [<br> {<br> a: "a",<br> b: "b"<br> },<br> {<br> c: "c",<br> d: “d”<br> }<br> ]<br>];</blockquote>
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</section>
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## Instructions
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<section id='instructions'>
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We have defined a variable called <code>yourArray</code>. Complete the statement by assigning an array of at least 5 elements in length to the <code>yourArray</code> variable. Your array should contain at least one <dfn>string</dfn>, one <dfn>number</dfn>, and one <dfn>boolean</dfn>.
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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: yourArray is an array
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testString: 'assert.strictEqual(Array.isArray(yourArray), true, "yourArray is an array");'
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- text: <code>yourArray</code> is at least 5 elements long
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testString: 'assert.isAtLeast(yourArray.length, 5, "<code>yourArray</code> is at least 5 elements long");'
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- text: <code>yourArray</code> contains at least one <code>boolean</code>
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testString: 'assert(yourArray.filter( el => typeof el === "boolean").length >= 1, "<code>yourArray</code> contains at least one <code>boolean</code>");'
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- text: <code>yourArray</code> contains at least one <code>number</code>
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testString: 'assert(yourArray.filter( el => typeof el === "number").length >= 1, "<code>yourArray</code> contains at least one <code>number</code>");'
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- text: <code>yourArray</code> contains at least one <code>string</code>
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testString: 'assert(yourArray.filter( el => typeof el === "string").length >= 1, "<code>yourArray</code> contains at least one <code>string</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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let yourArray; // change this line
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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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