Arrays & Tuples

TypeScript provides two syntaxes for arrays and support for tuples.

Array Syntax

// Two equivalent syntaxes
let numbers: number[] = [1, 2, 3];
let strings: Array<string> = ["a", "b", "c"];

// Array methods are type-safe
numbers.push(4);  // OK
// numbers.push("5");  // Error: string not assignable to number

Tuples

// Fixed-length arrays with specific types
let tuple: [string, number] = ["age", 30];
let coords: [number, number, number] = [10, 20, 30];

// Optional elements
let optional: [string, number?] = ["name"];

// Rest elements
let rest: [string, ...number[]] = ["values", 1, 2, 3];

Readonly Arrays

let readonlyArray: readonly number[] = [1, 2, 3];
// readonlyArray.push(4);  // Error: push doesn't exist on readonly array