Basic Methods in Array

1. Array.length This Method is used to find the length of the given array,its return type is number

const days = ["sunday","monday","tuesday","wednesday","thursday","friday","saturday"]

let size = days.length // output : 7

2.Array.toString()
This Method returns the entire array as a coma seperated string, return type string

const days = ["sunday","monday","tuesday","wednesday","thursday","friday","saturday"]

let size = days.toString() // output :sunday,monday,tuesday,wednesday,thursday,friday,saturday

3.Array at()
This Method returns the value of the specified index inside the braces,
return type depends on the value on that index

const days = ["sunday","monday","tuesday","wednesday","thursday","friday","saturday"]

let day = days.at(2) // output : tuesday

4.Array join()
This Method joins the array with specified character inside the braces, return type is string

const days = ["sunday","monday","tuesday","wednesday","thursday","friday","saturday"]

let week = days.join("-") // output : sunday-monday-tuesday-wednesday-thursday-friday-saturday

5.Array pop()
This Method is used to pop the last element from the array

const days = ["sunday","monday","tuesday","wednesday","thursday","friday","saturday"]

let week = days.pop() // output : sunday,monday,tuesday,wednesday,thursday,friday

6.Array push()
This method adds a new element to an array at the end

const days = ["sunday","monday","tuesday","wednesday","thursday","friday"]
let week = days.push("saturday") // output : sunday,monday,tuesday,wednesday,thursday,friday,saturday

7.Array shift()
This method removes the first array element and "shifts" all other elements to a lower index

const days = ["sunday","monday","tuesday","wednesday","thursday","friday"]
let week = days.shift() // output : monday,tuesday,wednesday,thursday,friday,saturday

8.Array unshift()
This method adds a new element to an array (at the beginning), and "unshifts" older elements

const days = ["monday","tuesday","wednesday","thursday","friday"]
let week = days.unshift("sunday") // output : sunday,monday,tuesday,wednesday,thursday,friday,saturday

9.Array.isArray()
This Method checks if the variable given inside its braces is actually an array or not, return type boolean

const days = ["monday","tuesday","wednesday","thursday","friday"]
let check = Array.isArray(days) // output : true

10.Array delete()
This Method deletes the given index inside the array but leave its position undefined, its is not highly recommended

const days = ["monday","tuesday","wednesday","thursday","friday"]
delete days[2];
console.log(days); // output ['monday', 'tuesday', empty, 'thursday', 'friday']

11.Array concat()
This method creates a new array by merging (concatenating) existing arrays

const days = ["monday","tuesday","wednesday"]
const nextDays = ["thursday","friday"]

const week = nextDays.concat(days);
output : thursday,friday,monday,tuesday,wednesday

12.Array copyWithin()
method copies array elements to another position in an array

const days = ["monday","tuesday","wednesday","thursday","friday"]
let week = days.copyWithin(2,0)
output :'monday', 'tuesday', 'monday', 'tuesday', 'wednesday'

13.Array flat()
This method creates a new array with sub-array elements concatenated to a specified depth
const days = [["monday","tuesday"],["wednesday","thursday"],"friday"]
let week = days.flat(); output : ["monday","tuesday","wednesday","thursday","friday"]

14.Array slice()
This method slices out a piece of an array into a new array by the given index

const days = ["monday","tuesday","wednesday","thursday","friday"]
let week = days.slice(2);// output : 'wednesday', 'thursday', 'friday'

15.Array splice()
This method can be used to add new items to an array at the given index

const days = ["monday","tuesday","wednesday","thursday","friday"]
days.splice(5,0,"saturday")// output : 'monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday'

16.Array toSpliced()
The difference between the new toSpliced() method and the old splice() method is that the new method creates a new array, keeping the original array unchanged, while the old method altered the original array

const days = ["monday","tuesday","wednesday","thursday","friday"]
let week = days.toSpliced(0,1); output : 'tuesday', 'wednesday', 'thursday', 'friday'