Was ist TypeScript?

TypeScript is a superset of JavaScript, meaning any valid JavaScript code is also valid TypeScript. What TypeScript adds is a type system — the ability to declare what type of data a variable should hold, what arguments a function expects, and what shape an object should have. This lets your code editor and compiler catch errors before you even run the code.

Developed by Microsoft, TypeScript has become the industry standard for large-scale JavaScript projects. It compiles down to regular JavaScript, so it runs anywhere JavaScript runs — browsers, Node.js servers, mobile apps, and more.

The benefits of TypeScript grow with project size. For a small script, types might feel like overhead. For a large application with multiple developers, types become essential documentation that's always up-to-date, a safety net that catches breaking changes, and a productivity tool that enables better autocomplete and refactoring.

TypeScript also makes APIs self-documenting. When a function's type signature clearly states what it accepts and returns, other developers (and your future self) can use it correctly without reading the implementation or hunting for documentation.