freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/declare-javascript-variables.md

---
id: bd7123c9c443eddfaeb5bdef
title: Declare JavaScript Variables
challengeType: 1
videoUrl: 'https://scrimba.com/c/cNanrHq'
forumTopicId: 17556
---

# --description--

In computer science, <dfn>data</dfn> is anything that is meaningful to the computer. JavaScript provides eight different <dfn>data types</dfn> which are `undefined`, `null`, `boolean`, `string`, `symbol`, `bigint`, `number`, and `object`.

For example, computers distinguish between numbers, such as the number `12`, and `strings`, such as `"12"`, `"dog"`, or `"123 cats"`, which are collections of characters. Computers can perform mathematical operations on a number, but not on a string.

<dfn>Variables</dfn> allow computers to store and manipulate data in a dynamic fashion. They do this by using a "label" to point to the data rather than using the data itself. Any of the eight data types may be stored in a variable.

`Variables` are similar to the x and y variables you use in mathematics, which means they're a simple name to represent the data we want to refer to. Computer `variables` differ from mathematical variables in that they can store different values at different times.

We tell JavaScript to create or <dfn>declare</dfn> a variable by putting the keyword `var` in front of it, like so:

```js
var ourName;
```

creates a `variable` called `ourName`. In JavaScript we end statements with semicolons. `Variable` names can be made up of numbers, letters, and `$` or `_`, but may not contain spaces or start with a number.

# --instructions--

Use the `var` keyword to create a variable called `myName`.

**Hint**  
Look at the `ourName` example above if you get stuck.

# --hints--

You should declare `myName` with the `var` keyword, ending with a semicolon

```js
assert(/var\s+myName\s*;/.test(code));
```

# --seed--

## --after-user-code--

```js
if(typeof myName !== "undefined"){(function(v){return v;})(myName);}
```

## --seed-contents--

```js
```

# --solutions--

```js
var myName;
```