The Beginner’s Guide to JavaScript Array with Examples

Javascript Array is a single variable that is used to store different elements. It is often used when we want to store a list of elements and access them by a single variable. An array is an object that can store multiple values at once.

Creating JavaScript arrays

You can create an array using two ways:

1) Using an array literal

The easiest way to create an array is by using an array literal [ ].

const array1 = ["pizza", "burger"];        

2) Using the new keyword

we can also create an array using JavaScript's new keyword.

const array1 = new Array("pizza", "burger");        

Thus, we can create an array using these both 2 ways. Let’s see more array examples.

// empty array
const myList = [ ];

// array of numbers
const num = [ 1, 3, 5, 7];

// array of strings
const str = [ 'pizza', 'burger', 'frenchfrice'];

// array with mixed data types
const mixed = ['work', 'exercise', 1, true];

console.log(myList);  // Output : [ ]
console.log(num);	  // Output : [ 1, 3, 5, 7 ]
console.log(str);	  // Output : [ 'pizza', 'burger', 'frenchfrice' ]
console.log(mixed);	  // Output : [ 'work', 'exercise', 1, true ]        

Access Elements of an Array

we can access elements of an array using indices (0, 1, 2 …).

const myArray = ['j', 'o', 'h', 'n'];

// first element
console.log(myArray[0]);	// Output : "h"

// second element
console.log(myArray[1]);	// Output :"e”        

Change the Elements of an Array

we can also add elements or change the elements by accessing the index value.

let person = [ 'john', 'carter'];

// this will add the new element ‘person' at the 2 index
person[2] = 'randy';

console.log(person);	// Output : [ 'john', 'carter', 'randy' ]        

Array length

You can find the length of an element (the number of elements in an array) using the length property.

const person = [ 'john', 'carter','randy'];

// this gives the total number of elements in an array
console.log(person.length);   // Output : 2        

Array Methods

In JavaScript, there are various array methods available that make it easier to perform useful calculations.

Method Description
concat() joins two or more arrays and returns a result
indexOf() searches an element of an array and returns its position
forEach() calls a function for each element
push() aads a new element to the end of an array and returns the new length of an array
pop() removes the last element of an array and returns the removed element
sort() sorts the elements alphabetically in strings and in ascending order
slice() selects the part of an array and returns the new array
splice() removes or replaces existing elements and/or adds new elements

Array Method examples

let person = ['John', 'Randy', 'Carter']
let newperson = ['Cena'];

// sorting elements in the alphabetical order
console.log(person);   // Output : [ 'Carter', 'John', 'Randy' ]

//finding the index position of string
const position = person.indexOf('Randy');
console.log(position); // Output :  2

// slicing the array elements
const newDailyActivities = person.slice(1);
console.log(newDailyActivities); // Output :  [ 'John', 'Randy' ]

// concatenating two arrays
const concat = person.concat(newperson);
console.log(concat);  // Output :[ 'Carter', 'John', 'Randy', 'Cena' ]        
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Ankit Patel

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