What is `callback(this[i])?`

Tell us what’s happening:
i don’t know understand **callback(this[i])** in this solution, pls help me !!!
what is callback(this[i]) for ?

// The global Array
var s = [23, 65, 98, 5];

Array.prototype.myMap = function(callback) {
  var newArray = [];

  // Add your code below this line
  for (let i = 0; i < this.length; i++) {
  // Add your code above this line

  return newArray;

var new_s = s.myMap(function(item) {
  return item * 2;

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Challenge: Implement map on a Prototype

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Thank you.

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callback is, well, a callback :stuck_out_tongue:
It’s a function you pass to myMap method; it will then be called once for each cycle of the loop you have written^^
this[i] refers to the caller (the array you will call myMap method against) at i index^^

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I will do it next time, thanks :heart_eyes:

Thks you so much.Now i have figured it out :heart_eyes:

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