Arrays aur Tuples

Ek typed array bilkul JavaScript array ki tarah kaam karta hai, lekin uska type annotation lock kar deta hai ki usme kis kism ki values ho sakti hain — string[] ka matlab hai strings ka array, aur TypeScript kisi aur cheez ko usme aane par flag kar dega.

main.ts

Khud try karo →

let fruits: string[] = ["apple", "banana", "cherry"];
console.log(fruits);
console.log(fruits[0]);

fruits.push("date");
console.log(fruits);

Output

[ 'apple', 'banana', 'cherry' ]
apple
[ 'apple', 'banana', 'cherry', 'date' ]

Tuples — fixed length, fixed types, koi JavaScript equivalent nahi

Tuple ek aisa array hai jiski fixed length hoti hai jahan har position ka apna specific type hota hai — position 0 hamesha ek string ho sakta hai, position 1 hamesha ek number. Plain JavaScript arrays mein yeh concept bilkul nahi hota; yeh sirf TypeScript ke type system mein exist karta hai.

main.ts

Khud try karo →

let point: [number, number] = [3, 4];
console.log(point);

let person: [string, number] = ["Alice", 30];
console.log(`${person[0]} is ${person[1]} years old`);

Output

[ 3, 4 ]
Alice is 30 years old

Runtime par tuple bas ek regular array hota hai — yeh farq sirf tab exist karta hai jab aap code likh rahe ho. point[0] ko ek string assign karne ki koshish karo, aur TypeScript aapko run hone se pehle hi rok dega.

Aage: objects aur interfaces — sirf ek single value nahi, ek object ka shape describe karna.

← Basic Types Objects aur Interfaces →