Constructors and the “this” keyword

Object Literals

const gabor = {
    name: 'Gabor',
    age: 36
}
console.log(gabor.name +' '+ gabor.age);

Constructor method

Person constructor with two property name and age

function Person(name, age){
    this.name = name;
    this.age = age;
    console.log(this);
}

const gabor = new Person('Gabor', 36);
const john = new Person('John', 40);

Object { name: "Gabor", age: 36 }
Object { name: "John", age: 40 }

Calculate age

function Person(name, dob){
    this.name = name;
    this.birthday = new Date(dob);

    this.calculateAge = function(){
        const diff = Date.now() - this.birthday.getTime();
        const ageDate = new Date(diff);
        return Math.abs(ageDate.getUTCFullYear() - 1970);
    }
}

const gabor = new Person('Gabor', '1984-11-24');

console.log(gabor.calculateAge());