The forEach polyfils - Javascript Interview Question

customForEach.js

Array.prototype.customForEach = function(fn) {
  const arr = this; 
  for(let i =0; i<arr.length; i++) {
    fn(arr[i], i, arr)
  }
};

const array = [1,2,3,4,5]; 

array.customForEach((item, i) => {
  console.log(item*2)
}); 

// output: 2 4 6 8 10