TypeScript - Interface

TypeScript Interface:
* Class can implement multiple interfaces.
* Define a interface with method contract.

Eg:
export interface Coach {
    getDailyWorkout(): string;
}

import { Coach } from "./Coach";
export class GolfCoach implements Coach {
    getDailyWorkout(): string {
        return "Hit 100 balls at the golf range.";
    } 
}

import { Coach } from "./Coach";
export class CricketCoach implements Coach {
    getDailyWorkout(): string {
        return "Practice your spin bowling technique.";
    }
}

import { CricketCoach } from "./CricketCoach";
import { GolfCoach } from "./GolfCoach";
import { Coach } from "./Coach";

let myCricketCoach = new CricketCoach();
let myGolfCoach = new GolfCoach();

// declare an array for coaches ... initially empty
let theCoaches: Coach[] = [];

// add the coaches to the array
theCoaches.push(myCricketCoach);
theCoaches.push(myGolfCoach);

for (let tempCoach of theCoaches) {
    console.log(tempCoach.getDailyWorkout());
}