f1c9b08cf3
This includes certificates (where it does nothing), but does not include any translations.
83 lines
1.8 KiB
Markdown
83 lines
1.8 KiB
Markdown
---
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id: 56bbb991ad1ed5201cd392ce
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title: Manipulate Arrays With unshift()
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challengeType: 1
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isHidden: false
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videoUrl: 'https://scrimba.com/c/ckNDESv'
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forumTopicId: 18239
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---
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## Description
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<section id='description'>
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Not only can you <code>shift</code> elements off of the beginning of an array, you can also <code>unshift</code> elements to the beginning of an array i.e. add elements in front of the array.
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<code>.unshift()</code> works exactly like <code>.push()</code>, but instead of adding the element at the end of the array, <code>unshift()</code> adds the element at the beginning of the array.
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Example:
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```js
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var ourArray = ["Stimpson", "J", "cat"];
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ourArray.shift(); // ourArray now equals ["J", "cat"]
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ourArray.unshift("Happy");
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// ourArray now equals ["Happy", "J", "cat"]
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```
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</section>
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## Instructions
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<section id='instructions'>
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Add <code>["Paul",35]</code> to the beginning of the <code>myArray</code> variable using <code>unshift()</code>.
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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: <code>myArray</code> should now have [["Paul", 35], ["dog", 3]].
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testString: assert((function(d){if(typeof d[0] === "object" && d[0][0] == 'Paul' && d[0][1] === 35 && d[1][0] != undefined && d[1][0] == 'dog' && d[1][1] != undefined && d[1][1] == 3){return true;}else{return false;}})(myArray));
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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 myArray = [["John", 23], ["dog", 3]];
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myArray.shift();
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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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(function(y, z){return 'myArray = ' + JSON.stringify(y);})(myArray);
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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 = [["John", 23], ["dog", 3]];
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myArray.shift();
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myArray.unshift(["Paul", 35]);
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```
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</section>
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