Variables

In coding, a variable is a designated word to store specific information. We can use variables to store names, amount, and other data.

A variable is a name used to store and keep track of information.
For example, you can keep track of how many coins you collect in a game by creating a "coins" variable.

Other examples of variables:

How does a variable work?

A variable is like a box.

You can put things in the box and you can take things out of the box.

For example:

apples_in_box = 10

apples_in_box = 8

apples_in_box = 9

Another example, in a game you may have a variable called "lives" which keeps track of how many lives you have left.

To create a variable in JavaScript, we use the let keyword or the var keyword or the const keyword.

In this course, we will often use the var keyword.

Example:

var userName= "James"

In the example above, the "userName" is the variable, and the information stored in the variable is "James".

JavaScript variables can hold numbers (like 100) and text values (like "Amy Wagner").

JavaScript has many data types, but in this class we will just focus on 3 data types:

Numbers: All numbers (including decimals and negative numbers). Example: 4.5, 300, -67
Strings: Texts, words, sentences are all called strings in coding. And they are written inside double quotes or single quotes. Example: "My school is amazing", "John", "Paris"
Boolean: True or false

Note:

Example of variables in JavaScript code:

Lesson 3: Variables and Functions