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Creating Arrays

Creating Arrays

Introduction

JavaScript offers multiple ways to create arrays: literals, constructors, Array.from(), and Array.of().

Array Literal (Recommended)

const fruits = ['apple', 'banana', 'orange'];
const mixed = [1, 'hello', true, null];
const empty = [];
const nested = [[1, 2], [3, 4]];

Array Constructor

const arr = new Array(5);    // Creates array of length 5 (empty slots)
const arr2 = new Array(1, 2, 3); // [1, 2, 3]

Array.from()

// From iterable
Array.from('hello'); // ['h', 'e', 'l', 'l', 'o']

// From array-like (with map function)
Array.from({ length: 3 }, (_, i) => i); // [0, 1, 2]

Array.of()

Array.of(5);    // [5] — unlike new Array(5)
Array.of(1, 2); // [1, 2]

Summary

Use array literals [] for most cases
Array.from() for converting iterables
Array.of() to avoid constructor ambiguity

Further Reading

MDN: Array Constructor