🔷 TypeScript

What you can learn on this page

• Intro & Why TypeScript — TypeScript vs JavaScript TypeScript is a statically typed superset of JavaScript developed by Microsoft. Every valid JavaScript file is also valid TypeScript — you adopt it incrementally without rewriting your entire codebase. TypeScript adds a compile step th
• Installation & Setup — Step 1 — Install Node.js LTS TypeScript runs on Node.js. Always install the LTS (Long-Term Support) release — it is the most stable version and is what CI/CD environments use. Download from https://nodejs.org and choose the 'LTS' button.
• Simple & Special Types — Simple Types TypeScript is JavaScript where every variable gets a label attached — like a box marked 'numbers only,' where trying to put the wrong thing in trips a warning before the box even closes (at compile time). So if simple types like number and string
• Arrays & Tuples — Arrays A TypeScript array is like a grocery aisle that won't let the product type drift — you can only put fruit on the 'fruit aisle' shelf, never a laptop in the middle of it. Java already did this with List<String>: a list that only accepts Strings. So
• Object Types & Enums — Object Types An object type is like a shipping manifest contract — it says 'this package must have a recipient name, a tracking code, and a weight,' and if one is missing, the box never leaves the warehouse. So why catch this before runtime, before the package
• Interface & Union Types — Union Types A union type is like a restaurant menu line reading 'choose a dessert: baklava OR rice pudding' — only one of those two ever arrives, a third option (say, soup) never shows up at the table. So why not just write `any` and say 'the ID can be anythin
• Functions & Casting — Functions A TypeScript function is like the terms of a will — 'I'm giving you these two things (parameters), and in return you must give me back something of this kind (the return type)'; if the promise isn't kept, nothing gets signed. So if a JavaScript funct
• Classes & Decorators — Classes A TypeScript class is like a shortened form of the same Java pattern — in Java, assembling a piece of furniture means first declaring the part (a field), then bolting it on by hand (`this.field = value` inside the constructor); in TypeScript, writing `