---
id: 56533eb9ac21ba0edf2244ab
title: Understanding Case Sensitivity in Variables
challengeType: 1
---
## Description
In JavaScript all variables and function names are case sensitive. This means that capitalization matters.
MYVAR is not the same as MyVar nor myvar. 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 do not use this language feature.
Best Practice
Write variable names in JavaScript in camelCase. In camelCase, multi-word variable names have the first word in lowercase and the first letter of each subsequent word is capitalized.
Examples:
var someVariable;
var anotherVariableName;
var thisVariableNameIsSoLong;
## Instructions
Modify the existing declarations and assignments so their names use camelCase.
Do not create any new variables.
## Tests
```yml
tests:
- text: studlyCapVar is defined and has a value of 10
testString: assert(typeof studlyCapVar !== 'undefined' && studlyCapVar === 10, 'studlyCapVar is defined and has a value of 10');
- text: properCamelCase is defined and has a value of "A String"
testString: assert(typeof properCamelCase !== 'undefined' && properCamelCase === "A String", 'properCamelCase is defined and has a value of "A String"');
- text: titleCaseOver is defined and has a value of 9000
testString: assert(typeof titleCaseOver !== 'undefined' && titleCaseOver === 9000, 'titleCaseOver is defined and has a value of 9000');
- text: studlyCapVar should use camelCase in both declaration and assignment sections.
testString: assert(code.match(/studlyCapVar/g).length === 2, 'studlyCapVar should use camelCase in both declaration and assignment sections.');
- text: properCamelCase should use camelCase in both declaration and assignment sections.
testString: assert(code.match(/properCamelCase/g).length === 2, 'properCamelCase should use camelCase in both declaration and assignment sections.');
- text: titleCaseOver should use camelCase in both declaration and assignment sections.
testString: assert(code.match(/titleCaseOver/g).length === 2, 'titleCaseOver should use camelCase in both declaration and assignment sections.');
```
## Challenge Seed
```js
// Declarations
var StUdLyCapVaR;
var properCamelCase;
var TitleCaseOver;
// Assignments
STUDLYCAPVAR = 10;
PRoperCAmelCAse = "A String";
tITLEcASEoVER = 9000;
```
## Solution
```js
var studlyCapVar;
var properCamelCase;
var titleCaseOver;
studlyCapVar = 10;
properCamelCase = "A String";
titleCaseOver = 9000;
```