409c39abf1
* feat(curriculum): Add Basic JS Scrimba links * Fix: Add missing video url. * fix: update videoUrl
76 lines
1.8 KiB
Markdown
76 lines
1.8 KiB
Markdown
---
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id: 56533eb9ac21ba0edf2244ba
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title: Understand String Immutability
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/cWPVaUR'
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---
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## Description
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<section id='description'>
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In JavaScript, <code>String</code> values are <dfn>immutable</dfn>, which means that they cannot be altered once created.
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For example, the following code:
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<blockquote>var myStr = "Bob";<br>myStr[0] = "J";</blockquote>
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cannot change the value of <code>myStr</code> to "Job", because the contents of <code>myStr</code> cannot be altered. Note that this does <em>not</em> mean that <code>myStr</code> cannot be changed, just that the individual characters of a <dfn>string literal</dfn> cannot be changed. The only way to change <code>myStr</code> would be to assign it with a new string, like this:
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<blockquote>var myStr = "Bob";<br>myStr = "Job";</blockquote>
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</section>
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## Instructions
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<section id='instructions'>
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Correct the assignment to <code>myStr</code> so it contains the string value of <code>Hello World</code> using the approach shown in the example above.
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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>myStr</code> should have a value of <code>Hello World</code>
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testString: assert(myStr === "Hello World", '<code>myStr</code> should have a value of <code>Hello World</code>');
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- text: Do not change the code above the line
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testString: assert(/myStr = "Jello World"/.test(code), 'Do not change the code above the line');
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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 myStr = "Jello World";
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// Only change code below this line
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myStr[0] = "H"; // Fix Me
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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(v){return "myStr = " + v;})(myStr);
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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 myStr = "Jello World";
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myStr = "Hello World";
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```
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</section>
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