--- id: bd7123c9c443eddfaeb5bdef title: Declare JavaScript Variables challengeType: 1 videoUrl: 'https://scrimba.com/c/cNanrHq' forumTopicId: 17556 dashedName: declare-javascript-variables --- # --description-- In computer science, data is anything that is meaningful to the computer. JavaScript provides eight different data types 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. Variables 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 declare 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; ```