C# vs TypeScript: Key Differences and When to Use Each

C# is a statically typed, compiled language mainly used for backend and desktop apps running on .NET, while TypeScript is a statically typed superset of JavaScript that compiles to JavaScript and is mainly used for web frontend and Node.js development. Both add type safety, but C# runs on a virtual machine, and TypeScript runs in browsers or JavaScript engines.

Quick Comparison

Here is a quick side-by-side look at C# and TypeScript on key factors.

Factor	C#	TypeScript
Typing	Static, strong	Static, gradual
Compilation	Compiled to IL (Intermediate Language)	Compiled to JavaScript
Runtime	.NET CLR (Common Language Runtime)	JavaScript engine (browser/Node.js)
Primary Use	Backend, desktop, games	Frontend web, Node.js backend
Tooling	Visual Studio, JetBrains Rider	VS Code, WebStorm
Ecosystem	.NET libraries, Windows integration	JavaScript libraries, web APIs

Key Differences

C# is a full-featured object-oriented language designed for building large-scale applications on the .NET platform. It supports advanced features like async/await, LINQ for data queries, and strong type safety enforced at compile time. It compiles to an intermediate language that runs on the .NET runtime, which manages memory and execution.

TypeScript is a superset of JavaScript that adds optional static types and modern language features. It compiles down to plain JavaScript, which means it can run anywhere JavaScript runs, such as browsers or Node.js. TypeScript's type system is gradual, allowing you to add types incrementally, which helps when working with existing JavaScript codebases.

While both languages improve code quality with types, C# is typically used for backend services, desktop apps, and games, whereas TypeScript is focused on web development and scripting environments. Their ecosystems and runtime environments differ significantly, influencing how and where you use each.

Code Comparison

Here is a simple example showing how to define a class and a method that returns a greeting in C#.

csharp

using System;

public class Greeter
{
    private string name;

    public Greeter(string name)
    {
        this.name = name;
    }

    public string Greet()
    {
        return $"Hello, {name}!";
    }
}

public class Program
{
    public static void Main()
    {
        var greeter = new Greeter("Alice");
        Console.WriteLine(greeter.Greet());
    }
}

Output

Hello, Alice!

TypeScript Equivalent

The equivalent TypeScript code defines a class and method similarly, but compiles to JavaScript to run in browsers or Node.js.

typescript

class Greeter {
    private name: string;

    constructor(name: string) {
        this.name = name;
    }

    greet(): string {
        return `Hello, ${this.name}!`;
    }
}

const greeter = new Greeter("Alice");
console.log(greeter.greet());

Output

Hello, Alice!

When to Use Which

Choose C# when building backend services, desktop applications, or games that benefit from a mature, strongly typed environment and the .NET ecosystem. It is ideal for Windows integration and large-scale enterprise projects.

Choose TypeScript when developing web frontends or Node.js backends where JavaScript compatibility is essential. It is best for projects needing gradual typing and seamless integration with existing JavaScript libraries and tools.

Key Takeaways

C# is a compiled, strongly typed language mainly for backend and desktop apps on .NET.

TypeScript adds static types to JavaScript and runs anywhere JavaScript runs.

Use C# for large-scale, performance-critical applications with rich tooling.

Use TypeScript for web development needing type safety and JavaScript compatibility.

Both improve code quality but serve different runtime environments and ecosystems.