Get constructor/instance from generic type in TypeScript

Question

I am trying to create instance from generic type T for example,

class Factory {
    public static generate(): T { 
      return new T()         


        

Answer 1

The type information used in TypeScript is erased before runtime, so the information about T is not available when you make the call to new T().

That's why all of the alternate solutions depend upon the constructor being passed, such as with this example of creating a class dynamically:

interface ParameterlessConstructor<T> {
    new (): T;
}

class ExampleOne {
    hi() {
        alert('Hi');
    }
}

class Creator<T> {
    constructor(private ctor: ParameterlessConstructor<T>) {

    }
    getNew() {
        return new this.ctor();
    }
}

var creator = new Creator(ExampleOne);

var example = creator.getNew();
example.hi();