Essential JavaScript

Introduction

JavaScript Intro

JavaScript Basics

Numbers

Add and Subtract

Plant Purchase Kata

Multiply and Divide

Apple Baskets Kata

Cake Slices Kata

Modulus and Remainders

Dogs and Bones Kata

Order of Operations

Flower Food Kata

Strings

Phrase Builder Kata

Using Quotes in a String

Escaping Characters

Name Length Kata

String Characters

Logic

Comparison Operators

Strict Equality

Equal Values Kata

Conditionals (if)

You Must Be This Tall Kata

Conditionals (else)

Sorting Shoes Kata

Biggest Pumpkin Kata

Order of Operations 2

Team Scores Kata

Vegetarian Menu Kata

Variables

Empty Variables

Utilizing Variables

Naming Variables

Dance Class Kata

Increment / Decrement

Variables with Let

Variables with Const

Variables Summary

Loops

Looping Over Numbers

Looping Over Strings

Count Letters Kata

Breaking a Loop

Button Combo Kata

Continuing a Loop

Picky Numbers Kata

Do...While Loop

Reverse Word Kata

Stretchy Word Kata

Objects

Intro to Objects

Objects vs Primitives

Build-a-Bot Kata

Accessing Properties

Updating Properties

Age Verification Kata

Arrays

Array Builder Kata

Human Names Kata

Longest Array Kata

Looping Over Arrays

Highest Number Kata

Word Hunter Kata

Array Average Kata

Adding Elements

Number Range Kata

Removing Elements

Arrays of Objects

Biggest Animal Kata

Arrays of Arrays

Taboo Words Kata

Going Further

Essential JavaScript

Introduction

JavaScript Intro

JavaScript Basics

Numbers

Add and Subtract

Plant Purchase Kata

Multiply and Divide

Apple Baskets Kata

Cake Slices Kata

Modulus and Remainders

Dogs and Bones Kata

Order of Operations

Flower Food Kata

Strings

Phrase Builder Kata

Using Quotes in a String

Escaping Characters

Name Length Kata

String Characters

Logic

Comparison Operators

Strict Equality

Equal Values Kata

Conditionals (if)

You Must Be This Tall Kata

Conditionals (else)

Sorting Shoes Kata

Biggest Pumpkin Kata

Order of Operations 2

Team Scores Kata

Vegetarian Menu Kata

Variables

Empty Variables

Utilizing Variables

Naming Variables

Dance Class Kata

Increment / Decrement

Variables with Let

Variables with Const

Variables Summary

Loops

Looping Over Numbers

Looping Over Strings

Count Letters Kata

Breaking a Loop

Button Combo Kata

Continuing a Loop

Picky Numbers Kata

Do...While Loop

Reverse Word Kata

Stretchy Word Kata

Objects

Intro to Objects

Objects vs Primitives

Build-a-Bot Kata

Accessing Properties

Updating Properties

Age Verification Kata

Arrays

Array Builder Kata

Human Names Kata

Longest Array Kata

Looping Over Arrays

Highest Number Kata

Word Hunter Kata

Array Average Kata

Adding Elements

Number Range Kata

Removing Elements

Arrays of Objects

Biggest Animal Kata

Arrays of Arrays

Taboo Words Kata

Going Further

← Human Names Kata

Essential JavaScript

Longest Array Kata →

← Prev Next →

Essential JavaScript

Introduction

JavaScript Intro

JavaScript Basics

Numbers

Add and Subtract

Plant Purchase Kata

Multiply and Divide

Apple Baskets Kata

Cake Slices Kata

Modulus and Remainders

Dogs and Bones Kata

Order of Operations

Flower Food Kata

Strings

Phrase Builder Kata

Using Quotes in a String

Escaping Characters

Name Length Kata

String Characters

Logic

Comparison Operators

Strict Equality

Equal Values Kata

Conditionals (if)

You Must Be This Tall Kata

Conditionals (else)

Sorting Shoes Kata

Biggest Pumpkin Kata

Order of Operations 2

Team Scores Kata

Vegetarian Menu Kata

Variables

Empty Variables

Utilizing Variables

Naming Variables

Dance Class Kata

Increment / Decrement

Variables with Let

Variables with Const

Variables Summary

Loops

Looping Over Numbers

Looping Over Strings

Count Letters Kata

Breaking a Loop

Button Combo Kata

Continuing a Loop

Picky Numbers Kata

Do...While Loop

Reverse Word Kata

Stretchy Word Kata

Objects

Intro to Objects

Objects vs Primitives

Build-a-Bot Kata

Accessing Properties

Updating Properties

Age Verification Kata

Arrays

Array Builder Kata

Human Names Kata

Longest Array Kata

Looping Over Arrays

Highest Number Kata

Word Hunter Kata

Array Average Kata

Adding Elements

Number Range Kata

Removing Elements

Arrays of Objects

Biggest Animal Kata

Arrays of Arrays

Taboo Words Kata

Going Further

Essential JavaScript

Introduction

JavaScript Intro

JavaScript Basics

Numbers

Add and Subtract

Plant Purchase Kata

Multiply and Divide

Apple Baskets Kata

Cake Slices Kata

Modulus and Remainders

Dogs and Bones Kata

Order of Operations

Flower Food Kata

Strings

Phrase Builder Kata

Using Quotes in a String

Escaping Characters

Name Length Kata

String Characters

Logic

Comparison Operators

Strict Equality

Equal Values Kata

Conditionals (if)

You Must Be This Tall Kata

Conditionals (else)

Sorting Shoes Kata

Biggest Pumpkin Kata

Order of Operations 2

Team Scores Kata

Vegetarian Menu Kata

Variables

Empty Variables

Utilizing Variables

Naming Variables

Dance Class Kata

Increment / Decrement

Variables with Let

Variables with Const

Variables Summary

Loops

Looping Over Numbers

Looping Over Strings

Count Letters Kata

Breaking a Loop

Button Combo Kata

Continuing a Loop

Picky Numbers Kata

Do...While Loop

Reverse Word Kata

Stretchy Word Kata

Objects

Intro to Objects

Objects vs Primitives

Build-a-Bot Kata

Accessing Properties

Updating Properties

Age Verification Kata

Arrays

Array Builder Kata

Human Names Kata

Longest Array Kata

Looping Over Arrays

Highest Number Kata

Word Hunter Kata

Array Average Kata

Adding Elements

Number Range Kata

Removing Elements

Arrays of Objects

Biggest Animal Kata

Arrays of Arrays

Taboo Words Kata

Going Further

Sign in to save your progress

Array Length

Like strings, arrays have a length property.

const letters = ['a', 'b', 'c', 'd'];
console.log(letters.length);

const numbers = [1, 2, 3, 4, 5, 6];
console.log(numbers.length);

Learning Goals

I can access the length of an array

Code Editor

Click "Run Code" to execute your JavaScript in a secure sandbox and see the output below.

Console Output

// Console output will appear here...

0 output lines