Basic Types in TypeScript

TypeScript allows you to define the type of data your variables will store. This helps make your code more predictable and easier to understand.

Primitive Types

The most common types are:

• string: text values;
• number: numeric values;
• boolean: true or false.

let name: string = "John";
let age: number = 25;
let isActive: boolean = true;

Arrays

You can also define arrays with a specific type:

let numbers: number[] = [1, 2, 3];
let users: string[] = ["Alice", "Bob"];

This ensures that all elements in the array follow the same type.

Type Inference

In many cases, TypeScript can automatically detect the type based on the assigned value.

let city = "New York";

TypeScript understands that city is a string, even without explicitly defining the type.

Why Types Matter

Types help prevent mistakes.

let price: number = 100;
price = "cheap"; // Error

Without TypeScript, this kind of issue might only appear at runtime. With TypeScript, it is caught immediately.