#javascript
Functions
Functions are the building blocks of JavaScript programs. They let you wrap up a piece of logic, give it a name, and reuse it whenever you need it. In the Introduction to JavaScript, we wrote a few simple functions. This tutorial goes much deeper — we’ll cover how JavaScript handles scope, what closures are, and how to use functions as values (higher-order functions). Function Declarations vs Expressions There are two main ways to define a function. Read more →
April 14, 2026
Arrays
Arrays are one of the most-used data structures in JavaScript. They’re ordered lists of values, and they come with a rich set of built-in methods for searching, transforming, and iterating over data. If you’ve worked through Functions, you’ve already seen map, filter, and reduce in passing — this tutorial covers arrays from the ground up. Creating Arrays // Array literal (most common) const fruits = ["apple", "banana", "cherry"]; // Empty array const empty = []; // Arrays can hold mixed types (though you usually wouldn't) const mixed = [1, "hello", true, null, { name: "Alice" }]; // Array. Read more →
April 14, 2026
Variables and Data Types
In the Introduction to JavaScript, we touched on let, const, and the basic data types. This tutorial goes deeper — we’ll explore how JavaScript handles types under the hood, what type coercion actually does, and the practical patterns you’ll use daily like template literals, destructuring, and type checking. var, let, and const in Depth You already know the basics: use const by default, let when you need to reassign. But the differences go beyond reassignment — they affect scoping and hoisting. Read more →
April 3, 2026
Introduction to JavaScript
JavaScript is the programming language that makes websites interactive. While HTML gives a page its structure and CSS controls how it looks, JavaScript is what makes things happen — responding to clicks, updating content, validating forms, and much more. If you’ve ever clicked a button on a website and something changed without the page reloading, that was JavaScript at work. In this tutorial, we’ll cover the fundamentals you need to start writing JavaScript. Read more →
April 3, 2026
Calling LLM APIs with JavaScript
Time to write some code. In this tutorial, we’ll go from zero to making LLM API calls in JavaScript — setting up a project, making your first completion request, managing conversations, handling errors, and building a simple interactive chatbot. We’ll use the OpenAI API as the primary example since it’s the most widely used, but the patterns apply to any LLM provider. You should be familiar with the concepts from What is Generative AI? Read more →
March 28, 2026
Streaming Responses
When you make a standard LLM API call, you wait for the entire response to be generated before you see anything. For short answers that’s fine, but for longer responses the user stares at a blank screen for seconds. Streaming fixes this by sending tokens to the client as they’re generated, creating the “typing” effect you see in ChatGPT and other AI chat interfaces. This tutorial covers streaming in depth — how it works under the hood, implementation in both JavaScript and Python, and how to integrate streaming into web applications. Read more →
March 28, 2026
Error Handling & Rate Limits
LLM API calls fail. Servers go down, rate limits get hit, tokens exceed context windows, and networks time out. If your application doesn’t handle these failures gracefully, your users get cryptic errors or broken experiences. This tutorial covers the common failure modes, how to detect them, and how to build retry logic that keeps your application running. You should have read Calling LLM APIs with JavaScript or Calling LLM APIs with Python first. Read more →
March 28, 2026
Building a RAG Pipeline
In Introduction to RAG, we built a minimal RAG system with an in-memory store and simple documents. Now let’s build something closer to production: loading real documents, chunking them intelligently, using a vector database, and evaluating the results. We’ll build a documentation Q&A system — the most common RAG use case — using JavaScript, OpenAI, and Chroma as our vector database. Architecture Markdown files → Chunker → Embeddings → ChromaDB ↓ User question → Embedding → Vector search → Top chunks → LLM → Answer Setup mkdir rag-pipeline && cd rag-pipeline npm init -y npm install openai chromadb Add "type": "module" to package. Read more →
March 28, 2026
Node.js
Node.js is a powerful, server-side JavaScript runtime that allows you to build scalable and efficient network applications. Node.js is designed for server-side (back-end) development, although it can also be used to run desktop applications such as scripts, utility applications, or even video games. In this introductory tutorial, we’ll explore the basics of Node.js and guide you through creating your first Node server. Prerequisites Before we dive into Node.js, you’ll need to have the following installed on your computer: Read more →
November 4, 2023
JavaScript
Master JavaScript, the language of the web. From basics to advanced concepts like async programming and frameworks. Read more →
October 12, 2023