Lesson 5: Arrays, Tuples, and Objects

Typed Arrays

let scores: number[] = [80, 90, 95];
let fruits: string[] = ["Apple", "Banana", "Orange"];

Typed arrays make sure that only the correct type of value is stored inside the collection.

Tuples

let student: [string, number] = ["Ali", 20];

A tuple has a fixed number of elements, and each element can have its own specific type.

Objects

let book: { title: string; price: number } = {
  title: "Learning TypeScript",
  price: 39.99
};

Arrays of Objects

let students: { name: string; score: number }[] = [
  { name: "Ali", score: 88 },
  { name: "Siti", score: 92 }
];

Arrays of objects are common in real applications because they allow you to manage many records efficiently.

Summary

Arrays, tuples, and objects are essential building blocks in TypeScript. Strong typing makes these data structures safer and easier to understand.