indexOf & lastIndexOf

• Search an array for the specified element & return the index of the first such element found.
• If no element is found, -1 is returned.
• Take an optional second argument that specifies the array index at which to begin the search. If the second argument is omitted, indexOf() searches the array from the beginning to the end & lastIndexOf() searches the array from the end to the beginning.

let name = ["hemanta", "kumar", "sundaray", "kumar", "hemanta"]

console.log(name.indexOf("kumar")) // => 1

console.log(name.lastIndexOf("kumar")) // => 3

sort

• Sorts the elements of an array in place and returns the sorted array.
• When no argument is passed, the method sorts the elements in alphabetical order.

let alphabets = ["c", "b", "a"]

alphabets.sort()

console.log(alphabets) // => ["a", "b", "c"]

reverse

• Reverses the order of the elements of an array in place and returns the reversed array.

let name = ["hemanta", "kumar", "sundaray"]

name.reverse()

console.log(name) // => ["sundaray", "kumar", "hemanta"]