TypeScript
/Beginner
Basic Types
Definition
The primitive building blocks of the TypeScript type system: `string`, `number`, `boolean`, `null`, `undefined`, and `symbol`.
Explain Like I'm New
These are the fundamental labels you attach to your variables to tell TypeScript exactly what kind of data is allowed to live inside them.
Real World Example
Declaring a user profile: `let username: string = 'Alice'; let age: number = 25; let isActive: boolean = true;`
Common Use Cases
- •Annotating primitive variables
Terminal Output
bash / terminal
const firstName: string = "Alice";
const age: number = 30;
const isDeveloper: boolean = true;
// Arrays of basic types
const scores: number[] = [95, 80, 100];
const names: Array<string> = ["Alice", "Bob"]; // Alternative syntax
Interview Questions
basic
- What are the three most common primitive types in TS?
intermediate
- Should you use `Number` or `number` when typing?
advanced
- What is the `bigint` type?