JavaScript Arrays

Master array creation, manipulation, and advanced operations

Array Basics & Creation

📚 What Are Arrays?

Arrays are list-like objects that store multiple values in a single variable. They're perfect for managing collections of related data like shopping lists, user names, or scores.

const shopping = ["bread", "milk", "cheese"]

🏗️ Array Creation Syntax

Square Brackets [ ]

const fruits = ["apple", "banana", "orange"]

Mixed Data Types

const mixed = [42, "hello", true, [1, 2]]

Array Length

fruits.length // returns 3

🔢 Zero-Based Indexing

Arrays start counting from 0, not 1!

Index 0

"bread"

Index 1

"milk"

Index 2

"cheese"

Index 3

"hummus"

Interactive Shopping List

Current Array:

Length: 5

0"bread"

1"milk"

2"cheese"

3"hummus"

4"noodles"

Array representation: ["bread", "milk", "cheese", "hummus", "noodles"]

🔍 Find Items

🔄 Array Transformations

Numbers Array:

Original: [5, 2, 7, 6]

Cities Filter:

All cities: ["London", "Liverpool", "Totnes", "Edinburgh", "Manchester"]

🔗 String ↔ Array

String to Split:

split(",") result:

[]

Join Separator:

array.join(",") result:

""

Pro Tips

💡Arrays are zero-indexed: first item is at index 0, not 1

🎯Use push() to add, pop() to remove from end

⚡map() transforms, filter() selects items

🔄Use split() and join() to convert strings ↔ arrays