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.