Array methods in javascript.

There are some methods in array

1.push()
2.unshift()
3.pop()
4.shift()
5.splice()
6.slice()
7.indexOf()
8.includes()
9.forEach()
10.map()
11.filter()
12.find()
13.some()
14.every()
15.concat()
16.join()
17.sort()
18.reduce()

1 Push() method

*Add new element at last position.

syntax

array.push(element1, element2, ..., elementN)

Example

let fruits = ['apple', 'banana'];
let newLength = fruits.push('orange', 'mango');

console.log(fruits); // Output: ['apple', 'banana', 'orange', 'mango']
console.log(newLength); // Output: 4

2 unshift() method

*Add new element at initial position.

syntax

array.unshift(item1, item2, ..., itemN)

Example

const fruits = ["Banana", "Orange", "Apple"];
fruits.unshift("Lemon");
console.log(fruits); // Output: ["Lemon", "Banana", "Orange", "Apple"]

3 pop() method

*It will remove your last element.
*It will return the removed element from the array
*"undifined" if the array is empty

syntax

array.pop();

Example

const fruits = ['Apple', 'Banana', 'Cherry'];
const lastFruit = fruits.pop();
console.log(fruits); // Output: ['Apple', 'Banana']
console.log(lastFruit); // Output: 'Cherry'

4 shift() method

*It will remove your first element.
*It will return the removed element from the array

syntax

array.shift();

Example

const fruits = ['Apple', 'Banana', 'Cherry'];
const firstFruit = fruits.shift();
console.log(fruits); // Output: ['Banana', 'Cherry']
console.log(firstFruit); // Output: 'Apple'

5 splice() method

*Adds or remove elements from an array.

*splice() will modified original array.

syntax

array.splice(start, deleteCount, item1, item2, ...);

Example

let colors = ['Red', 'Green', 'Blue'];
colors.splice(1, 0, 'Yellow', 'Pink'); // Adds 'Yellow' and 'Pink' at index 1
console.log(colors); // Output: ['Red', 'Yellow', 'Pink', 'Green', 'Blue']

6 slice() method

*It is used to extract(give) the part of array.
*slice will return array.
*slice will not modified the original array.

syntax

array.slice(start, end);

Example

let numbers = [2, 3, 5, 7, 11, 13, 17];
let newArray = numbers.slice(3, 6);
console.log(newArray); // Output: [7, 11, 13]

7 indexOf() method

*The indexOf() method in JavaScript is used to find the first index at which a given element can be found in the array, or -1 if the element is not present.

syntax

array.indexOf(searchElement, fromIndex);

Example

let fruits = ['Apple', 'Banana', 'Orange', 'Banana'];
let index = fruits.indexOf('Banana');
console.log(index); // Output: 1

8 includes() method

*It is used to identify certain element is present in our array or not.
*If element is present it will return "true" otherwise return "false".
*It will return boolean value.

syntax

array.includes(searchElement, fromIndex);

Example

let numbers = [1, 2, 3, 4, 5];
let hasThree = numbers.includes(3, 2);
console.log(hasThree); // Output: true

9 forEach() method

• Executes the function for each element.
• Does not create a new array.
• Original array remains unchanged.

Example

let numbers = [1, 2, 3];
numbers.forEach((value, index, arr) => {
arr[index] = value * 2;
});
console.log(numbers); // Output: [2, 4, 6]

10 map() method

• It takes each element of an array.
• The output of map array is always array only.
• It will not change original array
• Creates a new array.

Example

const numbers = [10, 20, 30];
const incremented = numbers.map((num, index) => num + index);
console.log(incremented); // Output: [10, 21, 32]

11 filter() method

• It is used to filter elements or data from the array based on certain condition.
  • If it return 'true' what ever data is store in this parameter that data will return.
  • If it return 'false' then it will not return any value it returns empty array
  • Creates a new array.
  • Original array remains unchanged.

Example

const numbers = [1, 2, 3, 4, 5, 6];
const evenNumbers = numbers.filter(num => num % 2 === 0);
console.log(evenNumbers); // Output: [2, 4, 6]

12 find() method

• It returns the first element of array for which call back function return true.
  • It return 'undifined' if the element is false or not satisfies.
  • Original array remains unchanged.

Example

const numbers = [1, 3, 4, 9, 8];

function isEven(element) {
return element % 2 === 0;
}

const firstEven = numbers.find(isEven);
console.log(firstEven); // Output: 4

13 some() method

• Returns true if at least one element passes the test.
• Returns false if no elements pass the test.
• Stops testing once the first passing element is found. *Original array remains unchanged.

Example

const numbers = [2, 4, 6, 8, 10];

const hasGreaterThanFive = numbers.some(num => num > 5);
console.log(hasGreaterThanFive); // Output: true

14 every() method

• It test all the elements in the array if all the condition satisfy then it return true.
• If one condition is not satisfy then it return false.
• Original array remains unchanged.

Example

const numbers = [10, 20, 30, 40, 50];

const allGreaterThanFive = numbers.every(num => num > 5);
console.log(allGreaterThanFive); // Output: true

15 concat() method

*Combine two or more arrays and returns a new array.

Example

const fruits = ['Apple', 'Banana'];
const vegetables = ['Carrot', 'Peas'];
const grains = ['Rice', 'Wheat'];

const food = fruits.concat(vegetables, grains);
console.log(food); // Output: ['Apple', 'Banana', 'Carrot', 'Peas', 'Rice', 'Wheat']

16 join() method

*Create a new string by concatenating all the elements of an array and
return a string by a specified separator.

Example

const letters = ['J', 'o', 'i', 'n'];
const result = letters.join('');
console.log(result); // Output: 'Join'

17 sort() method

*It is used to arrange the element of an array in place and return the sorted array.

• By default the sort method sorts the element as strings in ascending order.

Example1

const numbers = [4, 2, 5, 1, 3];
numbers.sort((a, b) => a - b);
console.log(numbers); // Output: [1, 2, 3, 4, 5]

Example2

const numbers = [4, 2, 5, 1, 3];
numbers.sort((a, b) => b - a);
console.log(numbers); // Output: [5, 4, 3, 2, 1]

18 reduce() method

• perform some operations and reduce the array to a single value.

Example

let number = [1, 2, 3, 4, 5];
let sum = number.reduce((accumulator, currentValue) => {
return accumulator + currentValue;
}, 0);

console.log(sum);

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