index.ts

// re-defined the person object before
//// with modification of role property: enum

// defined enum Role
// enum Role { ADMIN, READ_ONLY, AUTHOR };
// //            0        1         2

// you can specify the enum value
enum Role { ADMIN = "ADMIN", READ_ONLY = 500, AUTHOR = "AUTHOR" };
//              "ADMIN"           500             "AUTHOR"         

// const person: {
//     name: string;
//     age: number;
//     hobbies: string[];
//     role: [number, string];         // tuple
// } = {
const person = {
    name: "Sarah",
    age: 24,
    hobbies: ["Cooking", "Reading"],
    role: Role.ADMIN               // enum Role
};

// person.role.push("admin");           // EXCEPTION
// person.role[1] = 0;                  // ERROR element index 1 only receives string
// person.role = [0, "admin", "user"];  // ERROR only receives 2 elements [number, string]

console.log(person.role);