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JavaScript Map Guides

The JavaScript Map functionality is used consistently to iterate over arrays in a consise and useful way. Use these guides to dive into all the JS Map nuance.

This is a collection of top and trending guides written by the community on subjects related to JavaScript Map concepts. For all things JavaScript, check out the JavaScript tag! Please contribute more posts like this to help your fellow developer in need.

How to use async/await with map and Promise.all

I found myself stuck on using the map function with async and await. It took me relearning how to work with promises to figure it out, but once I figured it out, the syntax turned out to be pretty nice and readable.

Drawing a Mind Map with Three.js and React

Starting from a root node Interests, my mind map is branching out to sub-nodes representing my interests Music, Graphic Design and Coding, which in turn have other sub-nodes, and so on.

filter, map and reduce in JS. When and Where to use??

The map method is used to iterate over an array. In each iteration, it applies a callback function on the current array element and finally returns a completely new array.

Example for google map with vue.js without vue library

I want use google map in vue.js.

It's enable when use like vue2-google-map library, but I want more directry use google API.

How to integrate Mapbox GL JS in your Next.js Project without react-map-gl or a React wrapper library

It started out as a curiosity and then turned into a solution that's live on production. For the record, I always recommend following the path of least resistance. If a React component library around Mapbox like react-map-gl works for you, stick with it! It has certainly served me well in the past.

Exporting Leaflet Map to Image in the Browser

Leaflet is a popular JavaScript map component library with an extensive ecosystem of plugins and integrations. I have been using it in several projects and it works really well as a UI component. At one point, I needed to produce a static image of the map with some overlays, which is something that Leaflet doesn't support out of the box, nor has a plugin that worked for me. Since the images would be produced based on user input, they had to be generated on the spot and not created in advance. My options were:

Use this trick to map over single objects in Javascript

How can we avoid this situation and make sure that we'll be able to map over the result, even if we get a single object after parsing the response? Let's look at the code bellow:

How to create a choropleth Map or Geographic HeatMap in React

A Choropleth Map is a thematic map in which areas are shaded or patterned in proportion to the measurement of the statistical variable being displayed on the map, such as population density or per-capita income.In this guide we’ll be creating a Choropleth map of Canada, But it can be used as a guide to create a similar map of any country. We’ll be using Datamap for this purpose. I am assuming that you are familiar with React.

How To: Draw a World Map with D3 in just 16 lines

Data-Driven Documents (D3) is a vast and powerful JavaScript library. It's pretty mindblowing that it lets you draw a map of the world, with all the countries in it in just 16 lines of code here.

Building a reactive scrolling map article in Svelte 🗺

Love it or hate it, Eater has a great interactive map listicle (mapicle? 🤔) format. For lists of places, it makes a complicated reading experience simple and fun. Here's an example if you've never read one.

React Native Map with real time location selection for Android

React Native Map with real time location selection for Android

Building map-based data visualizations with Mapbox, React, and Cube.js 🗺

As you most likely know, there are many ways to visualize data, but when it comes to location-based (or geospatial) data, map-based data visualizations are the most comprehensible and graphic.

Drawing a Mind Map with Force Directed Graphs

In the previous part I, part II and part III, I've found out how to render React components on sprites in three.js and connect them with lines to make up a mind map that's nested two levels deep.

How to create a COVID-19 map with Mapbox and React

In the current state of the world 🦠 and with many of us in lockdown, I thought it would be a good idea to put down Netflix for a bit, and build a COVID map similar to Hopkins Dashboard.

How to create map like in airbnb with react and google-maps

Let's assume that we need to create a map with displaying apartment cards on it as it is done on airbnb

The technology stack is next:

Creating an Interactive Map of the US

In this tutorial, we'll be learning how to create an interactive map of the US using HTML, CSS, and Javascript.

Building a Coffee Map with React Native

This Map component is a wrapper for Expo's MapView component. By making electing to wrap the built-in component we can decorate our map with functionality through lifecycle methods and application-specific methods, such as rendering the markers. Here, it is not implemented specific to our use case of finding coffee shops -- that decision is made in the App.js component that renders it.

JavaScript Map is getting upsert!

But Map is different. A Map is an object in JavaScript that holds key-value pairs.

How I built a weather forecast app with location map in React & Leaflet!

Called WeatherMan React hosted on Github Pages, link to github profile here.

It is made in plain React (uses Context, no fancy Redux needed). Styling is done using Bootstrap and SASS.

You can search any location from a huge list of over 100,000 places and fetch 7 day weather forecast. Additionally, I also added a location map shown in Leaflet where you can show layers made of temperature, cloudy etc.

Weather service used is OpenWeatherMap - It has a one call API which returns Hourly and Minutely forecast too.

Here's a little image snippet:

Recursive approach to map and reduce: A thought experiment

In my early stages of learning Elixir, I had to write a recursive implementation of the functions map and reduce. It turned out to be a simple albeit extremely interesting exercise. I was struck by the elegance and simplicity of such implementations.

Drawing a Mind Map with Three.js and React, for Real This Time

In the previous part, I've found out how to render React components on sprites in three.js. My plan is to create a mind map. So far I've got the root node of my mind map displayed, yay!

Functional Programming: Using the map Method to Extract Data from an Array

The map method iterates over each item in an array and returns a new array containing the results of calling the callback function on each element. It does this without mutating the original array.

Adding a Custom Popup to a Map Layer Using React

The aim of this post is to provide an introduction to adding a variety of spatial data formats to a React application using Mapbox GL JS. Understanding how to add sources and layers to a map will open a lot of doors for the types of applications you can build using Mapbox GL JS.

Let's create our map method

It's very important to know that returns a new array which means that the old array is not mutated. (Mutation is a very important concept when you start to work with React and Redux libraries). Enough talking, now let's code. Here is a simple example how map works.

Filter on map function in React JS

Hello Guys Today i am going to show you how you can apply filter on map function.

Advantages of a JavaScript Map

I wrote a previous blog post about JavaScript Set objects so I naturally wanted to follow it up with a post about JavaScript Map objects. Sets and Maps could be considered distant cousins or estranged siblings to the more popular and workhorse Arrays and Objects, and a Map in particular is like a hybrid Object/Array (okay, I may be the only one who considers this).

Building a 3D React Map Component Using Mapbox

The best part about the new release is just how easy it is to render 3D terrain. This post will walk you through how to create a React Map component with 3D terrain rendering. The process is more or less exactly what you would follow for creating any other Mapbox Gl JS map in React.

I made an adventure map for Oaxaca, Mexico and here's what I learned

In late 2018 / early 2019, I launched a map and adventure guide called Oaxaca Explorer. Oaxaca Explorer is meant to help Oaxaca travelers find hiking/biking trails, cabins, waterfalls, and other interesting off-the-beaten-path destinations to explore. I wrote this short piece to describe why/how I made it and what I learned.

Método Map para JavaScript y React

El método map transforma los elementos del array uno por uno aplicándoles una función en base al elemento y a su posición, dicha función es programada por nosotros de acuerdo a la necesidad es decir podemos usar condicionales, y distintas herramientas que la programación nos permita ejecutar siempre y cuando se ejecuten de forma síncrona

Build a Map Application on AWS in 10 Steps

Last week, the team I work on at AWS Amplify launched new map UI components. I wanted to take this opportunity to show what you can build using Amplify Geo and Amplify Studio together!

How to add source map to the esbuild configuration

In this article, I'll show you how to add a source map to the setup we developed so far in this series.

Ultimate Road Map to Study JavaScript : Basics to Advanced

Road Map to study JavaScript. Starting All the way from Basics to Advanced with references of useful links !

How to built your own Map | HTML , CSS , JavaScript & Leaflet.js in just 10 min

Hi folks ,

In this todays video you will get to learn how to built your own

Dynamic map with HTML , CSS , JavaScript & Leaflet.js . It is going to be to to much interesting with only little amount of code . In this video you will also come across through usage of API and its implementation.

This is going to be completely responsive design and map is going to be completely dynamic & you can search anything by search indexing used in map and this is one of best project for junior developers !

Writing a Functional Programming-Style map Function

Many thanks to Helen Durrant for reviewing this post and offering stellar suggestions. Originally posted on

Google Map With Draggable Marker Example

Today we will learn google map with draggable marker example. Here, we will see how to add google map in your website. Google map is used to display location or address, google provides user to google API key to google map implementation in laravel.

The Map Function in JavaScript

In this post we will learn how to use the Map Function in JavaScript. This particular function is very useful because not only can you map an array of objects, but also map elements.

Javascript - forEach vs map method in Arrays

The main difference between map and forEach is that map returns a new array whereas forEach returns undefined.

Still Trying to Draw a Mind Map with Three.js and React

In the previous part I and part II, I've found out how to render React components on sprites in three.js and connect them with lines to make up a mind map root node and the first level of child nodes, displayed around the root in a circle.

Differences between JavaScript Map and Object

Does this mean both map and object are similar to one another??

Well, both let us set keys to values, retrieve those values, delete keys, and detect whether something is stored at a key. Due to this reason, Objects were previously used as Maps. But there are important differences that make using a Map preferable in certain cases.

Create a temperature map with Mapbox and OpenWeatherMap

A temperature maps shows the current temperature in a color scale, from blue (cold) to red (hot). In this tutorial, I will show how to create a web-based temperature map using JavaScript, Mapbox, and OpenWeatherMap.

Happy JavaScript Map coding!