let numbers = [1, 2, 3, 4]
let filteredNumbers = numbers.map(function(_, index){if (index < 3){
return num
}})
// index goes from 0, so the filterNumbers are 1,2,3 and undefined.
// filteredNumbers is [1,2,3, undefined]
// numbers is still [1,2,3,4]
let arr = [1,2,3]
/*
map accepts a callback function, and each value of arr is passed to the
callback function. You define the callback function as you would a regular
function, you're just doing it inside the map function
map applies the code in the callback function to each value of arr,
and creates a new array based on your callback functions return values
*/let mappedArr = arr.map(function(value){
return value +1})
// mappedArr is:
> [2,3,4]
function square(arr){
const newArr = arr.map(x => x * x );
return newArr ;
//if you find this answer is useful ,
//upvote ⇑⇑ , so can the others benefit also . @mohammad alshraideh ( ͡~ ͜ʖ ͡°)
let numbers = [1, 2, 3, 4]
let filteredNumbers = numbers.map(function(num, index){if (index < 3){
return num
}})
// index goes from 0, so the filterNumbers are 1,2,3 and undefined.
// filteredNumbers is [1,2,3, undefined]
// numbers is still [1,2,3,4]