Create a new object from type parameter in generic class

by

To create a new object within generic code, you need to refer to the type by its constructor function. So instead of writing this:

function activatorNotWorking<T extends IActivatable>(type: T): T {
    return new T(); // compile error could not find symbol T
}

You need to write this:

function activator<T extends IActivatable>(type: { new(): T ;} ): T {
    return new type();
}

var classA: ClassA = activator(ClassA);

See this question:
Generic Type Inference with Class Argument

More Related Contents:

  1. Generic type to get enum keys as union string in typescript?
  2. TypeScript how to create a generic type alias for a generic function?
  3. Typescript: infer type of generic after optional first generic
  4. Why can’t I return a generic ‘T’ to satisfy a Partial?
  5. How to create a Partial-like that requires a single property to be set
  6. Typescript, merge object types?
  7. In TypeScript, how to get the keys of an object type whose values are of a given type?
  8. Parameters generic of overloaded function doesn’t contain all options
  9. Higher-order type functions in TypeScript?
  10. ‘compile-time’ way to get all property names defined interface
  11. Typescript ReturnType of generic function
  12. Is it possible to generate string literal combinations with template literal in TypeScript?
  13. Iterable cannot confirm generic T in function
  14. Getting the return type of a function which uses generics
  15. typescript difference between placement of generics arguments
  16. Is there a `valueof` similar to `keyof` in TypeScript?
  17. How do I dynamically assign properties to an object in TypeScript?
  18. Does Typescript support the ?. operator? (And, what’s it called?)
  19. error TS2339: Property ‘x’ does not exist on type ‘Y’
  20. Get properties of a class
  21. typescript template literal as interface key
  22. Difference between extending and intersecting interfaces in TypeScript?
  23. How to do runtime type casting in TypeScript?
  24. Accessing properties in union types
  25. How can I remove a wider type from a union type without removing its subtypes in TypeScript?
  26. Generating typescript declaration files from javascript
  27. How to get a variable type in Typescript?
  28. TypeScript export imported interface
  29. How to create an Observable from static data similar to http one in Angular?
  30. get dictionary/object keys as tuple in typescript

Leave a Comment