JSFiddle - React, Tailwind, and code Playground

JavaScript

let arr = [1,2,3,4,5]

arr.forEach(item => {
	console.log(item)
})

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

arr.customForEach(item => {
	console.log(item);
})