Can u tell me what is the function of (callback) and (x). Are they variables or object, method , parameter?

Tell us what’s happening:

Your code so far

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

Array.prototype.myFilter = function(callback){
  var newArray = [];
  // Add your code below this line
  this.forEach(function(x) {
    if (callback(x) == true) {
  // Add your code above this line
  return newArray;


var new_s = s.myFilter(function(item){
  return item % 2 === 1;

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Link to the challenge:

‘callback’ is a… callback function , myFilter is a higher order function. x represents an element of an array that forEach operates on.

function(x) {
    if (callback(x) == true) {

^^ This is a callback that gets passed as a parameter when calling forEach on an array. Honestly the examples of forEach on MDN are easy to understand, try looking there if you don’t understand what x is. You can also try reading this explanation:

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