Welcome to Codecademy Docs

Community-driven code documentations for popular programming languages and frameworks. If you're interested in contributing, check out our Contribution Guide or leave us some feedback.

Most Viewed

Arrays

Arrays are lists of ordered, stored data. They can hold items that are of any data type. Arrays are created by using square brackets, with individual elements separated by commas. js // An array containing numbers const numberArray = [0, 1, 2, 3]; // An array containing different data types const mixedArray = [1, chicken, false];

Built-in Functions

The Python interpreter has a set of functions and types built into it (pre-defined). They are always ready at your disposal; you can use them without needing to import a library. There are 68 built-in functions and they are listed here in alphabetical order.

Attributes

HTML attributes can be added to the opening tag of an HTML element to change the elements default behavior or provide additional information about the element. They consist of a name and a value using the following syntax: name="value". pseudo So for example, the image element has a mandatory src attribute that contains the image file path/URL: html

Classes

Classes are templates used to define the properties and methods of objects in code. They can describe the kinds of information that the class holds, and also how a programmer interacts with that data. It serves as a blueprint or template for the objects, or "instances" of the class. In Python, classes are defined using the class keyword. py class Animal: def init(self, name, leg_count): self.name = name

Aggregate Functions

In SQL, aggregate functions perform a calculation on a set of values and return a single value. They are often used with the GROUP BY clause of the SELECT statement. Note: Except for COUNT(), aggregate functions ignore all NULL values. List all the years and their number of movies, but only the years with more than 5 movies: sql SELECT year, COUNT() FROM movies

What is Next.js?

Next.js is an open-source development framework building server-side rendering and static web applications using React. Typical React apps use the client-side browser to upload content, Next.js is unique in that it is a React framework built on top of Node.js. This helps curtail certain issues such as a user not having access to JavaScript. This also enables Next.js to render content on the server-side before it can be viewed by the client. Next.js was originally authored by Guillermo Rauch on GitHub in 2016 and due to its functionality, large companies such as Netflix, Starbucks, Uber, GitHub, and Ticketmaster have all used Next.js for their website development. It is currently owned and maintained by the company Vercel. Fun Fact: Codecademy Docs is written with Next.js.

Concept of the Week

What is Next.js?

Next.js is an open-source development framework building server-side rendering and static web applications using React. Typical React apps use the client-side browser to upload content, Next.js is unique in that it is a React framework built on top of Node.js. This helps curtail certain issues such as a user not having access to JavaScript. This also enables Next.js to render content on the server-side before it can be viewed by the client. Next.js was originally authored by Guillermo Rauch on GitHub in 2016 and due to its functionality, large companies such as Netflix, Starbucks, Uber, GitHub, and Ticketmaster have all used Next.js for their website development. It is currently owned and maintained by the company Vercel. Fun Fact: Codecademy Docs is written with Next.js.

Recently Added

Decorators

Decorators are a structural design pattern that wrap the original object, to add extra functionality dynamically, without modifying the original object. Decorators are usually used to run code before and/or after a function. Thus, they decorate the function with additional functionality, without changing the original function. They can also be used to alter the functionality of methods and classes.

What is GraphQL?

Memory Management

Modules

Concept of the Week

What is Next.js?

Next.js is an open-source development framework building server-side rendering and static web applications using React. Typical React apps use the client-side browser to upload content, Next.js is unique in that it is a React framework built on top of Node.js. This helps curtail certain issues such as a user not having access to JavaScript. This also enables Next.js to render content on the server-side before it can be viewed by the client. Next.js was originally authored by Guillermo Rauch on GitHub in 2016 and due to its functionality, large companies such as Netflix, Starbucks, Uber, GitHub, and Ticketmaster have all used Next.js for their website development. It is currently owned and maintained by the company Vercel. Fun Fact: Codecademy Docs is written with Next.js.

Recently Added

Decorators

Decorators are a structural design pattern that wrap the original object, to add extra functionality dynamically, without modifying the original object. Decorators are usually used to run code before and/or after a function. Thus, they decorate the function with additional functionality, without changing the original function. They can also be used to alter the functionality of methods and classes.

What is GraphQL?

Memory Management

Modules