declaration merge typescript code example

Example 1: 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
};

Example 2: typescript utility types merge interfaces

interface A {
    x: string
}

interface B extends Omit<A, 'x'> {
  x: number
}