Hello again, friends! The reduce() method is one of the most confusing Array methods in JavaScript. So in this article, I’m going to help you clearly see how the method works. I'm also going to show some examples that'll help you understand how and where you may want to  ( 7 min )

ECMAScript 2023, the 14th edition of the language, has some great changes that will make your programming life easier. In this article, I'll go through each of the changes and explain why they're helpful. So let’s dive in and see some new methods we got as an early Christmas  ( 4 min )

Hi everyone! In this article, I’m going to teach you one of the most confusing JavaScript topics, which is the Promise object. Promises may seem difficult at first, but they're actually quite simple once you understand how they work. Here's what we'll cover: 1. How a Promise Works  ( 11 min )

In today’s world of technology, we get more recommendations from Artificial Intelligence models than from our friends. Surprised? Think of the content you see and the apps you use daily. We get product recommendations on Amazon, clothing recommendations on Myntra, and movie suggestions on Netflix based on our past  ( 8 min )

Creating projects is very important for expanding your web development portfolio. Transforming an idea into a real project can help you to practice and understand key concepts and techniques. We just published a 3-hour course in Spanish on freeCodeCamp's Spanish YouTube channel [https://www.youtube.com/freecodecampespanol] that will teach you how to build  ( 4 min )

In this article, we'll thoroughly explore base64 encoding. You'll learn how it came into being and why it's still so prevalent in modern systems. Here's what we'll cover: 1. What is base64? 2. Why use base64? 3. When to use base64 4.  ( 13 min )

Python's beauty lies in its simplicity and readability. And mastering the art of writing concise yet powerful code can significantly enhance your productivity as a developer. I'm talking about really short lines of code that do big things. In this article, we'll explore 8 essential Python one-liners that every Pythonista  ( 8 min )

In this article, Sasha guides you through crucial processes and factors to achieve a consistent brand presence across platforms. She offers an overview of the entire brand identity process, explores collaboration with UI teams, and provides essential details on the assets required for the successful implementation of a digital brand.  ( 22 min )

Ethereum is one of the major pioneers in the decentralized ecosystem. And Web3.js is an essential tool if you're working on Ethereum-based projects. To fully understand why this tool is important, we must first take a deeper dive into Ethereum development. Grab your coffee, young Web3 enthusiast. We're going  ( 5 min )

Two-Factor Authentication, or 2FA, is like having an extra lock on the door to your online accounts. Instead of just using a password, 2FA adds another layer of security. It's a bit like needing both a key and a special code to open a vault. Think of it as a  ( 21 min )

Feature engineering is an essential step in the data preprocessing process, especially when dealing with tabular data. It involves creating new features (columns), transforming existing ones, and selecting the most relevant attributes to improve the performance and accuracy of machine learning models. Feature engineering helps the model understand  ( 7 min )

Interacting with external APIs, or Application Programming Interfaces, has become an essential skill in web development. APIs allow different software applications to communicate with each other, enabling developers to access and retrieve data from various sources. One popular way to perform API requests in JavaScript is by using  ( 7 min )

Scroll-based animations are triggered when a user scrolls on a webpage. Recently, I built a Scroll Animation with Framer Motion [https://www.aceternity.com/components/container-scroll-animation] that moves grids in uneven directions. This project prompted me to write a tutorial about how I did that here on freeCodeCamp. The Framer Motion library makes it super  ( 10 min )

The AWS Cloud Project Bootcamp is a free comprehensive training program to equip you with the skills and knowledge to successfully design, build, and implement a cloud project. We just published the entire 107-hour bootcamp on the freeCodeCamp.org YouTube channel. Andrew Brown from ExamPro developed this course. The AWS Cloud  ( 3 min )

On this week's episode of the freeCodeCamp Podcast, I interview hardware engineer and tech founder from Austria. We talk about growing up in the European countryside, his early passion for computers, and ultimately his move to San Francisco, where he's founded several tech companies. Bruno's super excited about embedded systems  ( 3 min )

Most people’s journey toward learning to program starts with a single late-night Google search. Usually it’s something like “Learn ______” But how do they decide which language to search for? > “They always joke about Java on Silicon Valley. I guess I should learn that.” Or: > “Haskell. So hot  ( 9 min )

2023 has been an amazing year for the freeCodeCamp community. I'm so grateful for the many kind volunteers who have helped us advance our mission of creating open learning resources. Over the past 12 months, the freeCodeCamp community has: * Merged 2,753 code contributions into our open source  ( 4 min )

We’re living in somewhat of a CSS renaissance with new features, techniques, experiments, and ideas coming at us to an extent we haven’t seen since “CSS3”. It’s easy to feel overwhelmed when your profession seems to be advancing at breakneck speed, but Geoff Graham considers the ways “modern” CSS in 2023 has actually made CSS “easier” to write.  ( 19 min )

A well-designed composable system should not only consider the technical aspects but also take into account the nature of the content it handles. To help us with that, we can use a Headless Content Management system such as Storyblok.  ( 15 min )

JavaScript, the language of the web, empowers developers to create dynamic and interactive web pages. One of the key features that enables this interactivity is Document Object Model (DOM) manipulation. DOM manipulation allows developers to interact with and modify the structure, style, and content of web pages. In this  ( 7 min )

Django model fields define the structure of a database within a Django web application. Using this essential component will keep your work organized and help you make fewer mistakes in your code. This article will discuss some common Django model fields and how to use them in your code. To  ( 7 min )

> Hey {username}, we've merged a PR before yours. Please resolve the merge conflicts so we can review and merge your PR. Have you ever received that kind of message from a maintainer while waiting for your pull request to be reviewed and merged? And then, you're panicking because you  ( 7 min )

Do you want to break into Data Science in 2024? Then you should consider trying to get your first Data Science internship. Internships can help you gain invaluable experience and set you up for success in the ever-evolving field of Data Science. But with fierce competition, limited opportunities, unclear  ( 30 min )

If you're regularly confronted by the complexity of modern data, you’re not alone. In our data-centric world, understanding data structures isn’t optional — it’s essential. Whether you’re a novice coder or an experienced developer, this handbook is your concise guide to the critical skill of data management through data structures. Data  ( 53 min )

Scikit-learn is an open-source machine learning library for Python, known for its simplicity, versatility, and accessibility. The library is well-documented and supported by a large community, making it a popular choice for both beginners and experienced practitioners in the field of machine learning. We just published an 18-hour course on  ( 3 min )

Go, or Golang, is a powerful programming language known for its simplicity, efficiency, and strong support for concurrent programming. It's a favorite among developers for building scalable web applications, cloud services, and more. We just released a Go course on the freeCodeCamp.org YouTube channel that walks you through building three  ( 3 min )

LangChain is an AI-first framework designed to enable developers to create context-aware reasoning applications by linking powerful Large Language Models with external data sources. We just published a course on the freeCodeCamp.org YouTube channel that will teach you all about LangChain. The course will equip you with the cutting-edge skills  ( 3 min )

What does the word career mean to you? To me, it is a roller coaster journey during which we find opportunities, progress, and growth in life. The journey involves learning objectives, work, and other personal and professional aspects. A promising career is one where you enjoy most (if not all)  ( 16 min )

In Part 1 of the series, Temani Afif demonstrated how creating ribbon patterns in CSS has evolved with the availability of new CSS features. In this second installment of this brief two-part series, we look at two additional ribbon variations that introduce techniques for masking a repeated background gradient in CSS.  ( 17 min )

Several months ago, I stumbled upon a coding challenge that intrigued me. Here's what it was: > Fun frontend question I was asked in an interview one time Build six squares with no color Every time you click one, it turns green When the last square turns green, they all  ( 8 min )

With the current state of the job market, there are a lot of people grinding out LeetCode [https://leetcode.com/] as a way to prepare for technical interviews. But sometimes it would be nice if there were a visualization showing the algorithms behind these problems. In this tutorial, we  ( 18 min )

User authentication is critical to mobile app development. It helps make sure that only authorized users can access sensitive information and perform actions within an application. In this tutorial, we will explore how to build secure user authentication in Flutter using Firebase for authentication and the Bloc state management pattern  ( 11 min )

Product teams benefit from knowing their users’ needs and how they respond to product updates as they build out the roadmap of a product. This article covers Voice of Customer programs and is aimed at those who work on a product team as well as executives who are looking for how to better inform your products using insight from users.  ( 25 min )

JavaScript is a powerful and versatile programming language that is widely used for creating dynamic and interactive web pages. One of the fundamental building blocks of JavaScript programming is the if statement. if statements allow developers to control the flow of their programs by making decisions based on  ( 7 min )

The python-telegram-bot v20 release introduced major structural changes. According to the documentation, > “All networking and I/O-related logic now works via coroutine functions (i.e. async def ... functions). In particular, all methods of the telegram.Bot class that make requests to the Bot API are now coroutine functions and need  ( 5 min )

Today I'm joined by Dr. Curran Kelleher. He's a data visualization expert and has taught a number of in-depth data visualization courses on freeCodeCamp's YouTube channel. We talk about what it's like to get a Ph.D. under one of the pioneers of data visualization. We also talk about how he  ( 3 min )

Effective collaboration between designers and developers is vital to creating good user experiences. However, bridging the handoff between design and development with the many tools and workflows available today has its pitfalls. Matthew Mattei introduces you to the Uno Platform, which offers a robust set of productivity boosters.  ( 25 min )

In this tutorial, you'll learn how to create a game that's inspired by Stick Hero – using pure JavaScript and HTML canvas. We are going to recreate Stick Hero [https://apps.apple.com/us/app/stick-hero/id918338898], a mobile game published by KetchApp. We'll go through how the game works in general, how to use JavaScript to  ( 23 min )

Have you ever wondered how websites can offer their content in multiple languages, perfectly tailored to different cultures and regions? Well, that magic is called localization, and it's a game-changer for web development – especially when using Django, a super versatile Python framework. It's not just about translating  ( 11 min )

In November of 2022, Artificial Intelligence took center stage in the tech world. AI was not a new concept, but OpenAI had just released its ChatGPT Large Language Model, and devs started diving into using it. Large Language Models, or LLMs, let users enter a prompt (some question or  ( 8 min )

React's ecosystem is always growing, and it seems like there are always new features and enhancements to make development more effective and user-friendly. React Suspense is one such feature that has become quite popular among React devs. In this guide, you'll learn all about React Suspense and examine its  ( 9 min )

You need to prepare if you want to perform well in technical developer job interviews. We just published a course on the freeCodeCamp.org YouTube channel that will guide you through every aspect of the technical interview process, as well as prepare you for the type of questions you might get  ( 3 min )

In this article, you will learn how to use TypeScript with React. By the end, you will have a solid understanding of how to write React code with TypeScript. Want to watch the video version of this tutorial? You can check out the video below: Table of Contents *  ( 16 min )

PaLM 2 is a cutting-edge AI tool from Google that opens up tons of possibilities for developers. The PaLM 2 API allows people to easily add generative AI to their apps. We just published a course on the freeCodeCamp.or YouTube channel that will teach you all about the PaLM 2  ( 3 min )

Ribbons have been used to accent designs for many years now. But, the way we approach them in CSS has evolved with the introduction of newer features. In this article, Temani Afif combines background and gradient tricks to create ribbon shapes in CSS that are not only responsive but support multi-line text and are easily adjustable with a few CSS variables.  ( 15 min )

Are you an aspiring engineering leader or a software developer looking to climb the ladder of success in your technical career? We just posted a course on the freeCodeCamp.org YouTube channel that will teach you how to be an exceptional engineering manager. Ankita Kulkarni teaches this course. She is an  ( 3 min )

Next.js is a React-based framework that enables developers to create full-stack web applications by extending the latest React features. Next helps you add additional features and optimizations to your React apps like static site generation (SSG), server-side rendering (SSR), automatic code splitting and bundling, and dynamic API routes.  ( 6 min )

While reading some technical articles on various platforms, I kept noticing the Table of Contents section in the sidebar. Some were interactive and some were just links to those sections. A Table of Contents usually ends up being pretty helpful to readers. It lets you easily skim through what  ( 6 min )

In the vast world of programming, scope is a fundamental concept. It underpins the behavior of variables in any given programming language. In the context of JavaScript, a language renowned for its widespread use in web development, understanding scope is crucial to writing efficient and bug-free code. Whether you're a  ( 14 min )

Earlier this year, my team at work and I were looking at the errors occurring in one of our signup APIs. We saw that nearly 5% of our requests were getting failed, all due to 400 BAD REQUEST [https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/400] errors. And the root cause was traced back to a regex  ( 9 min )

Words alone aren’t enough to safeguard best practices in the world of web design and development. Web design documentation must be like its medium — interactive and constantly evolving.  ( 17 min )

You know the saying “If you keep looking at the past, you’ll miss the future”? Well in the context of coding and working with Git, that’s not the case. Your commit history plays a huge role in the future of the open source projects that you contribute to, and  ( 5 min )

On this week's podcast, I meet with Arian Agrawal in New York City to talk about her journey into tech startups. Arian grew up in New York and studied at MIT. She worked in finance for a few years, then built her own ecommerce Marketplace startup with a friend. Along  ( 3 min )

Are you ready to elevate your expertise in designing cloud and hybrid solutions on Azure? The Azure Solutions Architect Expert Certification exam measures your ability to accomplish the following technical tasks: design identity, governance, and monitoring solutions; design data storage solutions; design business continuity solutions; and design infrastructure solutions. We  ( 4 min )

Animation and accessibility are often seen as two separate powers at odds with one another. How is it possible to strike a balance between elements that move and the possible negative effects they expose to users who are sensitive to motion? Oriana García explains how her team at Mercado Libre tackled the challenge by creating guiding principles for applying animation to user interfaces and incorporating them into the team’s design system.  ( 17 min )

This guide demonstrates the straightforward process of incorporating authentication into your Next.js app using the next-auth.js [https://next-auth.js.org/] library. While the library provides numerous options (providers), this tutorial focuses on the implementation using the Google Provider. You'll also gain insight into effortlessly setting up protected routes within your application, a task  ( 6 min )

Are you just getting into software development, or do you need to upgrade your coding skills? Java's significance within the tech sector stands unchallenged, so it's a great place to start. Java is at the foundation of Object-Oriented Programming (OOP). This is an approach to programming that mirrors our complexity  ( 86 min )

If you create Next.js apps, chanced are you are going to have to include user authentication at some point. We just posted a course on the freeCodeCamp.org YouTube channel that teaches how to implement authentication in Next.js 13.5 with the powerful library, NextAuth – which will soon be known  ( 3 min )

WordPress Playground began as an experiment to see what a self-hosted WordPress experience might look like without the requirement of having to actually install WordPress. A year later, the experiment has evolved into a full-fledged project. Ganesh Dahal demonstrates how WordPress Playground works and gets deep into how it might be used.  ( 25 min )

Hey there! So, you know that buzz about Tesla's autopilot being all futuristic and driverless? Ever thought about how it actually does its magic? Well, let me tell you – it's all about image segmentation and object detection. What is Image Segmentation? Image segmentation, basically chopping up an image  ( 8 min )

JavaScript is one of the most popular programming languages out there, and it's essential for web development. Learning JavaScript can be your next step into this amazing world of web dev. We just published a course on the freeCodeCamp.org Spanish YouTube channel [https://www.youtube.com/freecodecampespanol] that will teach you JavaScript from the  ( 4 min )

Arduino is an open-source electronics platform that allows you to create interactive devices with sensors and outputs. With Arduino, you can build DIY electronics projects with minimal technical knowledge. We just published a comprehensive Arduino course on the freeCodeCamp.org YouTube channel. The course covers the basics of Arduino, from hardware  ( 3 min )

If you're new to AWS, you can probably appreciate the sense of overwhelm that comes from trying to understand all the different services (seriously, like, hundreds of them). What are they all for, and how do they work together? And then once you've conquered some basic skills, the  ( 19 min )

In order to write scalable, reusable, and maintainable applications with React, you'll need to go beyond the surface of using React components, useEffect, useContext, useState, and the like. It involves learning in detail how React works in more depth. And if you don't properly understand these key React concepts,  ( 10 min )

In this tutorial, you will learn how to build a simple whiteboard app using Python and Tkinter. Some months ago, I was teaching a Python course. I was struggling to convey certain concepts because it was an online course, and I couldn't use a whiteboard or even a traditional board.  ( 9 min )

Declaring variables is something you'll do all the time in JavaScript. And if you know the variable declaration process inside and out, you'll have the confidence to start writing great JS code. Through this article, you will learn how to declare and mutate variables using var, let, and const,  ( 10 min )

If you're looking to add some polished animations to your React apps, Framer Motion is the tool for the job. In this tutorial, I'll walk you through creating a fully animated mobile menu using Framer Motion in React. What Are We Going to Build? In this tutorial, I'll guide  ( 8 min )

The combination of artificial intelligence (AI) and web development has revolutionized the way we create and manage online content. I just created and released a course on the freeCodeCamp.org YouTube channel that will teach you how to use AI to help create an e-commerce store powered by WordPress. You will  ( 3 min )

The CSS `clamp()` function is often paired with viewport units for “fluid” font sizing that scales the text up and down at different viewport sizes. As common as this technique is, several voices warn that it opens up situations where text can fail WCAG Success Criterion 1.4.4, which specifies that text should scale up to at least 200% when the user’s browser reaches its 500% maximum zoom level. Max Barvian takes a deep look at the issue and offers ideas to help address it.  ( 17 min )

The browser has a built-in way of writing reusable components in the form of web components. They’re an excellent choice for building interactive and reusable components that work in any frontend framework. With that said, writing highly interactive and robust web components isn’t simple. They require a lot of  ( 10 min )

Today I'm joined by Joel Spolsky. He's co-founder of Trello and Stack Overflow, and author of the iconic developer blog Joel on Software. I hung out with Joel in his New York City home to discuss his 4-decade-long career as a developer and a CEO. He shared his insights  ( 3 min )

Calling an API (Application Programming Interface) in JavaScript is a fundamental action that web developers need to know how to perform. It allows you to fetch data from external sources and integrate it into your web applications. In this tutorial, I'll walk you through the process of making API  ( 8 min )

TypeScript is taking over the web. In this article I'll give you a high-level overview of the benefits of TypeScript and how can it help you create websites with fewer bugs. You'll learn how TypeScript helps with handling edge cases, catching typos, refactoring code, and how types make code  ( 14 min )

Note: This article is by Julia Gustafsson. In the world of software development, innovation often arrives in the form of powerful tools that transform the way we build applications - enter Quarkus, a development platform that's reshaping the Java landscape. If you are new to the Quarkiverse, this tutorial  ( 20 min )

The freeCodeCamp community just finished participating in this year's Hacktoberfest – a month-long celebration of open source. Our core team is excited to recognize all of our wonderful open source contributors. A big thank you to all of these folks for the effort they put into helping improve our curriculum  ( 4 min )

Helper functions in React.js are like your trusty assistants, and they play a crucial role in simplifying complex tasks. When these functions are well-structured, they make your code easier to read, maintain, and reuse. In this article, we'll explore the significance of helper functions in React.js projects. We'll also  ( 11 min )

Are you a complete beginner interested in learning web development? Look no further! We just published a comprehensive course about web development with HTML and CSS on the freeCodeCamp.org YouTube channel. This course is thoughtfully designed and taught by Aakash N S, the CEO and co-founder of Jovian, a platform  ( 3 min )

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Icons are capable of enhancing the content that surrounds them, but they have to be self-explanatory for that to happen. We have icons for things we like (a thumbs up), things we can share (a box topped with an up arrow), and even for protection against malicious online attacks (a shield), but what are the options we have for representing “privacy”?  ( 18 min )

If you want to learn to code and get a job as a developer, you're in the right place. This book will show you how. And yes this is the full book – for free – right here on this page of freeCodeCamp. Update October 20, 2023: I've recorded a  ( 121 min )

React is a popular framework for building web applications. It's is one of the best options for frontend engineering because of its declarative approach to user interface design and component-based architecture. But it can be difficult to make sure your React application functions as intended in various different scenarios.  ( 19 min )

Infrastructure as Code (IaC) is a revolutionary approach to managing and provisioning computing infrastructure. With IaC, you can automate the process of provisioning, configuring, and managing infrastructure using code and software development techniques. This approach provides a more efficient, consistent, and reliable way of managing infrastructure compared to traditional manual  ( 20 min )

Looping through arrays in JavaScript is a fundamental concept that every JavaScript developer should understand. Whether you're a beginner or an experienced developer, understanding how to loop through an array is crucial for many programming tasks. In this article, we'll explore the different ways to loop through an array  ( 9 min )

Take a closer look at how various performance tools audit and report on performance metrics, such as core web vitals. Geoff Graham answers a set of common questions that pop up during performance audits.  ( 18 min )