Javascript

In the previous tutorial, we learned how to type functions. Now let’s learn how to describe the shape of objects — one of the most important skills in TypeScript. By the end of this tutorial, you will know how to define object types, use interfaces, extend them, and choose between interfaces and type aliases. Object Types You can describe an object’s shape by listing its properties and types: let user: { name: string; age: number } = { name: "Alex", age: 25, }; TypeScript checks that the object matches the shape: ...

In the previous tutorial, we learned the basic types in TypeScript. Now let’s learn how to use types with functions — the building blocks of every program. By the end of this tutorial, you will know how to type every kind of function in TypeScript. Function Parameter Types In TypeScript, you must add types to function parameters. TypeScript cannot infer parameter types: // JavaScript — no types function greet(name) { return "Hello, " + name; } // TypeScript — types required function greet(name: string) { return "Hello, " + name; } If you forget to add a type, TypeScript gives an error with strict: true: ...

In the previous tutorial, we installed TypeScript and wrote our first program. Now let’s learn the type system — the core feature that makes TypeScript useful. By the end of this tutorial, you will know every basic type in TypeScript and when to use each one. Type Annotations A type annotation tells TypeScript what type a variable should be. You add it after the variable name with a colon: let name: string = "Alex"; let age: number = 25; let isActive: boolean = true; The : string, : number, and : boolean are type annotations. If you try to assign the wrong type, TypeScript gives an error: ...

In the previous tutorial, we learned what TypeScript is and why it matters. Now let’s install it and write our first program. By the end of this tutorial, you will have TypeScript installed, VS Code configured, and a working project you built yourself. Step 1: Install Node.js TypeScript runs on Node.js. If you don’t have Node.js installed, download the LTS version from nodejs.org. After installation, verify it works: node --version # v22.x.x or later npm --version # 10.x.x or later If both commands print version numbers, you are ready. ...

TypeScript is everywhere. It became the #1 most-used language on GitHub in August 2025, surpassing Python. It now ranks among the top languages in every major developer survey. If you write JavaScript, TypeScript is no longer optional — it is expected. This tutorial series will take you from zero to confident TypeScript developer. We start here: what TypeScript actually is, and why you should learn it in 2026. What is TypeScript? TypeScript is a superset of JavaScript that adds static types. Every valid JavaScript file is already valid TypeScript. TypeScript just adds extra features on top. ...

Figma’s canvas engine runs in your browser at desktop speed. Google Earth loads a 3D globe without a plugin. AutoCAD moved from a desktop app to a website. They all use WebAssembly. What is WebAssembly? WebAssembly — Wasm — is a binary format that browsers can run directly. It is not a programming language. It is a compile target. You write code in C++, Rust, Go, or another language. You compile it to a .wasm binary. The browser loads that binary and runs it at near-native speed. ...