note.txt

//Class and Interface
interface IPrint{
    print();
}

function printClass(a:IPrint){
    console.log(a);
    return null;

}


class ClassA implements IPrint{
    print(){
        console.log(`ClassA.print() is called...`);
    }
}

class ClassB implements IPrint{
    print(){
        console.log(`ClassB.print() is called...`);
    }

}

let classA = new ClassA();
classA.print();
let classB = new ClassB();