Variables & Data Types

let, const, var and the primitive types.

Video tutorialTrack course · freeCodeCamp

JavaScript Full Course for Beginners

Speed

0.75x1x1.25x1.5x2x

Skip intro Next lesson

Watch 00:00 · 1 checkpoints Watch on YouTube More on this topic

Transcript & captions .txt

7/7

1. 00:00Variables & Data Types. let, const, var and the primitive types.
2. 00:05const — cannot be reassigned. Use it by default.
3. 00:10let — reassignable, block scoped.
4. 00:15var — function scoped and hoisted. Avoid it.
5. 00:20Primitive types: string, number, boolean, null, undefined, bigint, symbol.
6. 00:25Everything else (arrays, functions, dates) is an object.
7. 00:30Try it yourself — edit the sample and run it in the browser.

• const — cannot be reassigned. Use it by default.
• let — reassignable, block scoped.
• var — function scoped and hoisted. Avoid it.

Primitive types: string, number, boolean, null, undefined, bigint, symbol. Everything else (arrays, functions, dates) is an object.