Accessing Array Elements

Part of the Fundamentals section of Coddy's JavaScript journey — lesson 58 of 77.

In JavaScript, we use arrays to store multiple values in a single variable. Each value in an array is called an element, and each element has an index. The indices start from 0 to the length of the array minus one.

For example, take a look at the next array:

let myArray = ['a', 'b', 'c', 'd', 'e', 'f', 'g']

Element a is at index 0
Element b is at index 1
...
Element g is at index 6

To access an element of an array, we can use its index within square brackets. For example, to access the first element of an array named myArray, we would use myArray[0].

Here's an example:

let myArray = [10, 20, 30, 40, 50]
let element = myArray[2]

The variable element will hold the value 30 because it accesses the third element (which has an index of 2).

Challenge

Easy

Create a function named values that receives an array as an argument and prints all of the items in the array one after the other.

To iterate over an array use the .length property inside the for statement:

let myArray = [10, 20, 30, 40, 50]
for (let i = 0; i < myArray.length; i++) {
    console.log(myArray[i]);
}

This way i will iterate from 0 to myArray.length (not including) which is exactly all of the array indices.

Cheat sheet

Arrays store multiple values in a single variable. Each element has an index starting from 0:

let myArray = ['a', 'b', 'c', 'd', 'e', 'f', 'g']

Access elements using square brackets with the index:

let myArray = [10, 20, 30, 40, 50]
let element = myArray[2] // Returns 30

Iterate over arrays using .length property:

for (let i = 0; i < myArray.length; i++) {
    console.log(myArray[i]);
}

Try it yourself

function values(arr) {
    // Write code here
}

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Fundamentals

1Introduction

The Language Hello World!Comments Code Structure

4Operators Part 2

Logical Operators Part 1 Logical Operators Part 2 Recap - Simple Logic Logical Operators Part 3 Type Coercion

7Bill Split Calculator

Welcome Message Calculating The Tip And Total

Splitting The Bill

Formatted Output

10FizzBuzz with a Twist

Game Overview The FizzBuzz Function

Looping The Numbers

Adding The Twist

13Grocery List Tracker

Project Overview Add Item

Remove Item

View List

2Variables

Numbers String Boolean Naming Conventions Empty Variables Recap - Initialize Variables Constants

5Decision Making

If Statement If - Else Recap - Simple Calculator Nested If - Else Switch Statement

8Loops

For Loop While Loop Break Continue Recap - Factorial Do While Loop Nested Loop

11Arrays Part 1

Declaring an ArrayAccessing Array ElementsModifying Arrays Array Methods Part 1 Array Methods Part 2 Recap - Array Processor

14Final Challenges

Number Pyramid Double The Odds What To Buy