Lesson 1.4: JavaScript ES6 Variables & Data Types
Learn how let, const, primitive types, and objects function in modern JavaScript ES6.
Lesson 1.4: JavaScript ES6 Variables & Data Types
JavaScript provides 3 variable declaration keywords: var, let, and const.
Tip
Always default to const unless you explicitly know the variable value needs to be reassigned later.
1. Variable Scope Comparison
| Keyword | Scope | Re-assignable | Hoisted |
|---|---|---|---|
var | Function | Yes | Yes (undefined) |
let | Block | Yes | No (TDZ) |
const | Block | No | No (TDZ) |
CODEBLOCK0
Lesson FAQs — Frequently Asked Questions
Key questions and answers clarifying the core concepts of this lesson.
What is the primary objective of this lesson?
This lesson covers fundamental web technology principles and practical coding standards required for modern web development.
How can I practice the concepts demonstrated in this lesson?
What software do I need to get started?