Creating Your First Variable

Variables are labeled containers that store information you want to use later in your code.

What is a Variable?

• Container for data - Variables hold values like numbers, text, or other information
• Reusable references - Once created, you can use the variable name to access its value anywhere
• Dynamic storage - Variables can be updated with new values as your program runs

Defining Variables

In JavaScript there are 3 ways to define variables, but we will focus on just one for now: let.

Copylet variableOne
let name = "Sally"
let age = 25

Key Points:

• Optional value - You can create a variable without an initial value
• Single equals (=) assigns a value to a variable
• Variable names should be descriptive and meaningful
• Case sensitive - age and Age are different variables

Updating Variable Values

One of the powerful features of variables is that you can change their values:

Copylet score = 10
console.log(score) // Prints: 10

score = 15
console.log(score) // Prints: 15

score = "name"
console.log(score) // Prints: name

Benefits of Using Variables

• Readability: Makes your code easier to understand
• Maintainability: You can change values in one place without updating multiple lines
• Reusability: Use the same variable in different parts of your code

Best Practices

• Use descriptive names: age instead of a
• Use camelCase: firstName instead of first_name
• Minimize changing values: Try to avoid changing variable values frequently, as it can make your code harder to follow