Lesson 3.1: Variables & Data Types

Objective

Learn about variables in JavaScript, how to declare them, assign values, and manipulate their content.

What is a Variable?

• A variable acts like a box or container storing a piece of information known as its value.
• Example:

  let box;

Naming a Variable:

• Variable names should be descriptive and relevant.
• They follow the camelCase convention (e.g., userName, totalAmount).
• Restrictions:
  • Cannot start with a number.
  • Cannot be reserved keywords (like let).

Assigning a Value:

• After declaring a variable, we can assign a value to it.
• Example:

  let box;
  box = 8;

Data Types:

• Numbers: Numerical values, can be positive, negative, or decimals.
• Strings: Series of characters enclosed within quotation marks (either single ' ' or double " ").

Operators:

• Used to perform arithmetic operations on variables.
• Basic ones include: +, -, *, /.

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