What is TypeScript and why it improves web development

TypeScript is a typed superset of JavaScript developed by Microsoft. It adds static types, interfaces and advanced tooling to standard JavaScript, making code safer, more maintainable and professional.

Every valid JavaScript code is also valid TypeScript, but TypeScript adds a layer of safety that catches errors before compilation, not at runtime.

For .NET developers, TypeScript is the ideal companion: the same typed mindset of C# applied to the frontend world.

TypeScript compiles to standard JavaScript (ES5, ES6, ESNext) and works anywhere JavaScript works: browser, Node.js, Deno.

Key features

Feature	Description
Static types	string, number, boolean, union types, generics: errors caught at compile time.
Interfaces	Define contracts between components for more structured and documented code.
Enum	Typed enumerations like in C#, for readable constant values.
Generics	Parametric types for reusable and type-safe components.
Decorators	Metadata for classes and methods (used in Angular and NestJS).
Module system	ES6 import/export with complete type checking.
Strict mode	strict: true for the maximum level of safety and error prevention.

TypeScript integrates perfectly with the .NET stack:

Scenario	Integration
ASP.NET + SPA	ASP.NET Core backend with Angular/React frontend in TypeScript.
Blazor + TypeScript	Typed JS interop for JavaScript libraries used in Blazor.
API client	Automatic generation of TypeScript clients from OpenAPI/Swagger of your Web APIs.
Visual Studio	First-class TypeScript support with IntelliSense, refactoring and integrated debugging.
NSwag / Kiota	TypeScript SDK generation from .NET APIs for type-safe client consumption.

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