An array can hold multiple values at a time.
To create an array in JavaScript:
Create an Array in JavaScript by assigning it to square brackets
let myArray = [];Assigning values to Array in JavaScript
let myArray = [1, 2, 3];
//Access the values of Array
console.log(myArray[0]); // The output is: 1
console.log(myArray[1]); // The output is: 2
console.log(myArray[2]); // The output is : 3
console.log(myArray[3]); // The output is: undefinedUse length to get the number of elements in an Array
The length property returns the number of elements in an Array.
let myArray = [1, 2, 3];
console.log( myArray.length ); // The output is 3Push Method to add elements to Array
To add an element to an Array use the push method.
let myArray = [];
myArray.push(4);
console.log( myArray );
//The output is : [4]Pop Method: Remove the last element from the Array
The pop method removes the last element from the Array and returns that element.
let myArray = [1,2,3];
let lastElement = myArray.pop();
console.log( lastElement );
//The output is : 3Shift Method: Removes and returns the first element from the Array
let myArray = [1,2,3];
let firstElement = myArray.shift();
console.log( firstElement );
//The output is : 1 Splice Method: Removes elements from the Array from the index number specified
let myArray = [1,2,3,4];
myArray.splice(3,1);
console.log( myArray );
//The output is : [1,2,3]Note: 1 here indicates how may numbers to be deleted after the index number specified.
Splice method can also add elements to an Array.
let myArray = [1,2,3,4];
myArray.splice(3,1,5,6,7);
console.log( myArray );
//The output is: [1,2,3,5,6,7] Here element at index number 3 is deleted. The number of elements to be deleted is 1. So in the above myArray 4 is deleted. The elements 5,6,7 is then added to the array.
Below is the list of all the methods and properties of an Array.
JavaScript Array Properties
| constructor: | Function to create Array’s objects |
| length: | Gives you the number of elements in an array |
| prototype: | You can add properties and methods to an Array object using prototype |
JavaScript Array Methods
| concat(): | Joins two or more arrays, and return the joined array |
| copyWithin(): | To copy array elements within the array, to and from specified positions |
| entries(): | Returns Array Iteration Object |
| every(): | Checks applied to every element in an array to pass a test |
| fill(): | Fill array with a static value |
| filter(): | Creates a new array with some check applied |
| find(): | Returns first element in an array to comply with check |
| findIndex(): | Returns index of first element to comply with check |
| forEach(): | Call a function for each array element |
| from(): | Get array from an object |
| includes(): | Checks if an array contains the specified element |
| indexOf(): | Returns index position of the specified element |
| isArray(): | To check if object is an Array or not |
| join(): | Joins all elements of an array and create a string |
| keys(): | Returns an Array with the keys of the original array |
| lastIndexOf(): | Return index of the specified element startin from the last |
| map(): | A new array is created with the result of calling a function for each array element |
| pop(): | Removes the last element from array, and returns that element |
| push(): | Adds an element to the end of an array, and returns the new length |
| reduce(): | Reduces to a single value (going left-to-right) |
| reduceRight(): | Reduce to a single value (going right-to-left) |
| reverse(): | Reverse the order of elements |
| shift(): | Removes first element of array, and return that element |
| slice(): | Removes or adds a part of an array, and returns the new array |
| some(): | Checks if any of the elements in an array complies with a test |
| sort(): | Sort array elements |
| splice(): | Adds/Removes array elements |
| toString(): | Converts array elements to string |
| unshift(): | Add elements to the beginning of array, and return the new length |
| valueOf(): | Gets the primitive value of an array |