Class constructor type in typescript?

by

Edit: This question was answered in 2016 and is kind of outdated. Look at @Nenad up-to-date answer below.

Solution from typescript interfaces reference:

interface ClockConstructor {
    new (hour: number, minute: number): ClockInterface;
}
interface ClockInterface {
    tick();
}

function createClock(ctor: ClockConstructor, hour: number, minute: number): ClockInterface {
    return new ctor(hour, minute);
}

class DigitalClock implements ClockInterface {
    constructor(h: number, m: number) { }
    tick() {
        console.log("beep beep");
    }
}
class AnalogClock implements ClockInterface {
    constructor(h: number, m: number) { }
    tick() {
        console.log("tick tock");
    }
}

let digital = createClock(DigitalClock, 12, 17);
let analog = createClock(AnalogClock, 7, 32);

So the previous example becomes:

interface AnimalConstructor {
    new (): Animal;
}

class Animal {
    constructor() {
        console.log("Animal");
    }
}

class Penguin extends Animal {
    constructor() {
        super();
        console.log("Penguin");
    }
}

class Lion extends Animal {
    constructor() {
        super();
        console.log("Lion");
    }
}

class Zoo {
    AnimalClass: AnimalConstructor // AnimalClass can be 'Lion' or 'Penguin'
    
    constructor(AnimalClass: AnimalConstructor) {
        this.AnimalClass = AnimalClass
        let Hector = new AnimalClass();
    }
}

More Related Contents:

  1. Types and classes of variables
  2. Get argument types for function / class constructor
  3. Is there a `valueof` similar to `keyof` in TypeScript?
  4. difference between variables inside and outside of __init__()
  5. ‘POCO’ definition
  6. How does interfaces with construct signatures work?
  7. Is there currently anyway to concatenate two or more string literal types to a single string literal type in TypeScript right now?
  8. no default constructor exists for class
  9. How to exclude getter only properties from type in typescript
  10. Why duck typing is allowed for classes in TypeScript
  11. Is there a way to define type for array with unique items in typescript?
  12. Template in Fortran?
  13. TypeScript: Accept all Object keys that map to a specific type
  14. What exactly is a Class Factory?
  15. Returning a value in constructor function of a class
  16. Error: cannot bind non-const lvalue reference of type ‘int&’ to an rvalue of type ‘int’
  17. Assignment of objects in VB6
  18. How do you use the non-default constructor for a member?
  19. Extending Android Application class
  20. Difference between extending and intersecting interfaces in TypeScript?
  21. When to use Interface and Model in TypeScript / Angular
  22. C# static class constructor
  23. How to create a circularly referenced type in TypeScript?
  24. Swift and using class extension
  25. TypeScript keyof returning specific type
  26. Copy Groovy class properties
  27. Error: Cannot invoke an expression whose type lacks a call signature
  28. Static class initializer in PHP
  29. How do you refactor a God class?
  30. C++ Member Initializer List

Leave a Comment