81 lines
3.1 KiB
Markdown
81 lines
3.1 KiB
Markdown
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---
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id: 56533eb9ac21ba0edf2244ab
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title: Understanding Case Sensitivity in Variables
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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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In JavaScript all variables and function names are case sensitive. This means that capitalization matters.
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<code>MYVAR</code> is not the same as <code>MyVar</code> nor <code>myvar</code>. It is possible to have multiple distinct variables with the same name but different casing. It is strongly recommended that for the sake of clarity, you <em>do not</em> use this language feature.
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<h4>Best Practice</h4>
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Write variable names in JavaScript in <dfn>camelCase</dfn>. In <dfn>camelCase</dfn>, multi-word variable names have the first word in lowercase and the first letter of each subsequent word is capitalized.
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<strong>Examples:</strong>
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<blockquote>var someVariable;<br>var anotherVariableName;<br>var thisVariableNameIsSoLong;</blockquote>
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</section>
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## Instructions
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<section id='instructions'>
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Modify the existing declarations and assignments so their names use <dfn>camelCase</dfn>.<br>Do not create any new variables.
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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: <code>studlyCapVar</code> is defined and has a value of <code>10</code>
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testString: 'assert(typeof studlyCapVar !== "undefined" && studlyCapVar === 10, "<code>studlyCapVar</code> is defined and has a value of <code>10</code>");'
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- text: <code>properCamelCase</code> is defined and has a value of <code>"A String"</code>
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testString: 'assert(typeof properCamelCase !== "undefined" && properCamelCase === "A String", "<code>properCamelCase</code> is defined and has a value of <code>"A String"</code>");'
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- text: <code>titleCaseOver</code> is defined and has a value of <code>9000</code>
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testString: 'assert(typeof titleCaseOver !== "undefined" && titleCaseOver === 9000, "<code>titleCaseOver</code> is defined and has a value of <code>9000</code>");'
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- text: <code>studlyCapVar</code> should use camelCase in both declaration and assignment sections.
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testString: 'assert(code.match(/studlyCapVar/g).length === 2, "<code>studlyCapVar</code> should use camelCase in both declaration and assignment sections.");'
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- text: <code>properCamelCase</code> should use camelCase in both declaration and assignment sections.
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testString: 'assert(code.match(/properCamelCase/g).length === 2, "<code>properCamelCase</code> should use camelCase in both declaration and assignment sections.");'
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- text: <code>titleCaseOver</code> should use camelCase in both declaration and assignment sections.
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testString: 'assert(code.match(/titleCaseOver/g).length === 2, "<code>titleCaseOver</code> should use camelCase in both declaration and assignment sections.");'
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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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// Declarations
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var StUdLyCapVaR;
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var properCamelCase;
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var TitleCaseOver;
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// Assignments
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STUDLYCAPVAR = 10;
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PRoperCAmelCAse = "A String";
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tITLEcASEoVER = 9000;
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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 studlyCapVar;
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var properCamelCase;
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var titleCaseOver;
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studlyCapVar = 10;
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properCamelCase = "A String";
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titleCaseOver = 9000;
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```
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</section>
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