TypeScript static classes

Abstract classes have been a first-class citizen of TypeScript since TypeScript 1.6. You cannot instantiate an abstract class.

Here is an example:

export abstract class MyClass {             public static myProp = "Hello";    public static doSomething(): string {      return "World";    }}const okay = MyClass.doSomething();//const errors = new MyClass(); // Error

TypeScript is not C#, so you shouldn't expect the same concepts of C# in TypeScript necessarily. The question is why do you want static classes?

In C# a static class is simply a class that cannot be subclassed and must contain only static methods. C# does not allow one to define functions outside of classes. In TypeScript this is possible, however.

If you're looking for a way to put your functions/methods in a namespace (i.e. not global), you could consider using TypeScript's modules, e.g.

module M {    var s = "hello";    export function f() {        return s;    }}

So that you can access M.f() externally, but not s, and you cannot extend the module.

See the TypeScript specification for more details.

Defining static properties and methods of a class is described in 8.2.1 of the Typescript Language Specification:

class Point {   constructor(public x: number, public y: number) {     throw new Error('cannot instantiate using a static class');  }   public distance(p: Point) {     var dx = this.x - p.x;     var dy = this.y - p.y;     return Math.sqrt(dx * dx + dy * dy);   }   static origin = new Point(0, 0);   static distance(p1: Point, p2: Point) {     return p1.distance(p2);   } }

where Point.distance() is a static (or "class") method.