Is there a way to “extract” the type of TypeScript interface property?

Question

Let\'s suppose there\'s a typing file for library X which includes some interfaces.

interface I1 {
    x: any;
}

interface I2 {
    y: {
        a: I1,
             


        

Answer 1

An interface is like the definition of an object. Then y is a property of your I2 object, that is of a certain type, in that case "anonymous".

You could use another interface to define y and then use it as your y type like this

interface ytype {
   a: I1;
   b: I1;
   c: I1;
}

interface I2 {
    y: ytype;
    z: any;
}

You can put your interface in a file and use extract so you can import it in other files of your projects

export interface ytype {
   a: I1;
   b: I1;
   c: I1;
}



 export interface I2 {
        y: ytype;
        z: any;
    }

You can import it that way :

   import {I1, I2, ytype} from 'your_file'