PrototypeInheritance.js

function Person(first, last, age, gender, interests) {
    this.name = {
        first,
        last
    };
    this.age = age;
    this.gender = gender;
    this.interests = interests;
}
// declare 
Person.prototype.greeting = function () {
    alert('Hi! ' + this.name.first);
};

function Teacher(first, last, age, gender, interests, subject) {
    Person.call(this, first, last, age, gender, interests, subject);
    this.subject = subject;
}

Teacher.prototype = Object.create(Person.prototype);

Object.defineProperty(Teacher.prototype, 'constructor', {
    value: Teacher,
    enumerable: false,
    writable: true
});

Teacher.prototype.greeting = function () {
    var prefix;

    if (this.gender === 'male' || this.gender === 'Male') {
        prefix = 'Mr.';
    } else if (this.gender === 'female' || this.gender === 'Female') {
        prefix = 'Mrs.';
    } else {
        prefix = 'Mx.';
    }

    alert('Hello, my name is ' + prefix + ' ' + this.name.last + ' and I teach ' + this.subject + ' . ');
};

let person1 = new Person('janusz', 'zajkowski', 24, 'male', ['drinking vodka all day']);

let teacher1 = new Teacher('Dave', 'Griffiths', 31, 'male', ['football'], 'math');