Each item within an array is identified by a unique value, its index (or position in the array). I realized my mistake and decided to include a female character at the first position in the Array. Let fullNames = firstNames.map(firstName => firstName + lastName) With map(), we can take all names in the array and append the 'man' suffix to each and every one of them: let firstNames = The problem is that the names in this list are not complete – they are missing an important suffix. To illustrate how map() works in JavaScript, let's consider a list of names of some of our favourite Avengers. How to Use the map() method – Avengers Example map() takes in all elements in that array (A), performs a consistent action on each of those elements, and returns them into a new array (B). On one end, there is an array (A) you want to operate on. The doctor took each and every one of them, administered the vaccine to them, and returned them into a new line of vaccinated people. On one end, there is a group of people who are yet to be vaccinated. The doctor does this by iterating through the line. One-by-one, a doctor administers the vaccination to all of them.

This means that they are yet to be vaccinated. Imagine this: there is a queue of people outside a hospital waiting to be vaccinated. In this article, I will explain the map() method and illustrate how it works with some simple examples. If you are a beginner struggling to understand how to use the map() method or what exactly it does, then this article is for you. The callback function takes in three parameters: This method takes in a callback function which gets called for every new element it iterates over. Think of looping as a way to progress from one element to another in a list, while still maintaining the order and position of each element.

And one of the most useful is the map() method.Ī() is a built-in array method for iterating through the elements inside an array collection in JavaScript. When ES6 (EmcaScript 2015) came out, it ushered in a whole new set of methods for iterating over an array.

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