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In this tutorial, you will know about JavaScript Arrays.

JavaScript Arrays are used to store multiple values. It is used when we want to store a list of elements and access them with the help of a single variable. JavaScript Arrays can store elements of any data type. This feature is not available in most programming languages.

for example

const student = [“Student1”, “Student2”, “Student3”];

student is an array which is storing three values of the same data type.

Declaration of Arrays

Arrays can be declared by two methods:

Initially, the arrays are empty. the first method is always preferred over the second method.

Initialization of Arrays

• Initialization of first method

let arr = [10, 20, 30, 40, 50];

Also we can create an array like below:

//Empty array
const arr1 = [ ];

// array of numbers
const arr2 = [ 12, 24, 36, 48];

// array of strings
const arr3 = [ 'apple', 'banana', 'mango'];

// array of mixed data types element
const arr4 = ['apple', 'number', 11, false];

//Empty array
const arr1 = new Array();

// array of numbers
const arr2 = new Array(12, 24, 36, 48); 

// array of strings
const arr3 = new Array('apple', 'banana', 'mango');

// array with mixed data types
const arr4 =  new Array('apple', 'number', 11, false);

Access the array element

An array element can be accessed by the index number. The index always starts from 0.

syntax:

arrayname[ indexnumber ]

arr[0] –> this points to the first element of array arr.

for example:

let arr = [];
arr[0] = 10;
arr[1] = 20;
arr[2] = 30;
arr[3] = 40;
arr[4] = 50;

console.log(arr[0]); // 10
console.log(arr[1]); // 20
console.log(arr[2]); // 30
console.log(arr[3]); // 40
console.log(arr[4]); // 50

Array length

There is the function name length is used to find the length of an array, i.e., the total number of elements in an array.

const arr1 = new Array('apple', 'banana', 'mango'); 
console.log(arr1.length); // 3

How do change the Elements of an Array?

Array elements can be changed by accessing the index of an element.

const arr1 = new Array('apple', 'banana', 'mango'); 
arr1[0] = 'orange';
console.log(arr1);

Sort the array element

using the sort() method

const arr1 = new Array('apple', 'banana', 'mango'); 
arr1[0] = 'orange';
arr1.sort();
console.log(arr1);

Article Written By:: Ankita Kataria.

Check about Synchronous and Asynchronous JavaScript.

#JavaScript Arrays

Thank you !!