typescript merge object with interface code example

Example: merge two types typescript

interface IStudent {
    id: string;
    age: number;
}

interface IWorker {
    companyId: string;
}

type IStudentAlias = IStudent;

type ICustomType = IStudent | IWorker;

let s: IStudentAlias = {
    id: 'ID3241',
    age: 2
};