Here's an example: // JavaScriptįoo = 55 // foo has changed type from a string to a number - no problemįoo = 55 // ERROR - foo cannot change from string to number On the other hand, JavaScript is a dynamically typed language, meaning variables can change type. Static typing means that the type of a variable cannot be changed at any point in a program. The main reason for using TypeScript is to add static typing to JavaScript. TypeScript is a superset of JavaScript, meaning that it does everything that JavaScript does, but with some added features. TypeScript cheat sheet PDF What is TypeScript? This makes it easy to look up and revise concepts/syntax quickly.

I also made a TypeScript cheat sheet PDF and poster that summarizes this article down to one page.

All of the main TypeScript concepts (types, interfaces, generics, type-casting, and more.).How to set up a project with TypeScript.What is TypeScript and why should I learn it?.TypeScript has become increasingly popular over the last few years, and many jobs are now requiring developers to know TypeScript.īut don't be alarmed – if you already know JavaScript, you will be able to pick up TypeScript quickly.Įven if you don't plan on using TypeScript, learning it will give you a better understanding of JavaScript – and make you a better developer.

Typescript tutorial