? JavaScript Object Constructors

In JavaScript, object constructors are special functions used to create and initialize objects. They work like blueprints for creating multiple similar objects.

?? Syntax: Object Constructor Function

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

???? Create Objects Using new Keyword

let person1 = new Person("Alice", 25);let person2 = new Person("Bob", 30);console.log(person1.name); // "Alice"console.log(person2.age);  // 30

?? How It Works

1. A constructor function is defined (capitalized by convention).

2. The new keyword:

   • Creates an empty object: {}.

   • Sets this inside the constructor to that object.

   • Returns the new object.

? Adding Methods to Constructors

function Car(brand, year) {  this.brand = brand;  this.year = year;  this.getAge = function() {    return new Date().getFullYear() - this.year;  };}let myCar = new Car("Toyota", 2015);console.log(myCar.getAge()); // e.g., 10

? Constructor vs Object Literal

? Pro Tip: Use Prototypes for Shared Methods

function Dog(name) {  this.name = name;}Dog.prototype.bark = function() {  return this.name + " says woof!";};let dog = new Dog("Buddy");console.log(dog.bark()); // "Buddy says woof!"

? Summary

• Object constructors are custom functions to create objects.

• Use this to set properties and methods.

• Always use the new keyword to invoke a constructor.

• For efficiency, define methods on the prototype.

Would you like to see how this transitions into ES6 class syntax?