TYPESCRIPT

typescript valueof interface

type ValueOf<T> = T[keyof T];

typescript object of type interface

const modal = {} as IModal;

typescript typeof interface property

interface I1 {
    x: any;
}

interface I2 {
    y: {
        a: I1,
        b: I1,
        c: I1
    }
    z: any
}

let myVar: I2['y'];  // indexed access type