Important array methods

1. concat()
Joins two or more arrays, and returns a copy of the joined arrays

the fullName will show Pritom Deb

2. every((element, index, array) => { /* ... */ })
Checks if every element in an array pass a test

teenager will reply true while adult while reply false. The every() method only returns true or false. The every() method does not execute the function for empty elements. The every() method does not change the original array

3. filter((element, index, array) => { /* ... */ })
Creates a new array with every element in an array that pass a test

adult will return a new array ["18","19","20"]

4. find((element, index, array) => { /* ... */ })
Returns the value of the first element in an array that pass a test

adult will return 18.

5. findIndex((element, index, array) => { /* ... */ })
Returns the index of the first element in an array that pass a test

adult will return 3.

6. forEach((element, index, array) => { /* ... */ })
Calls a function for each array element

adult will return undefined. It is very important to note that forEach only iterate through a array. It doesn't return any value.

7. Array.form(arrayLike, (element, index) => { /* ... */ })
Creates an array from an object

nameArray will return ["p", "r", "i", "t", "o", "m"]

8. includes(searchElement)
Calls a function for each array element

adult will return undefined. It is very important to note that forEach only iterate through a array. It doesn't return any value.