What is constructor in JavaScript?

In JavaScript, a constructor is a special function used to create and initialize objects.
Simple idea

A constructor is like a blueprint for creating multiple similar objects.

1. Constructor function (old/classic way):

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

const p1 = new Person("Praveen", 25);
const p2 = new Person("Kumar", 30);

console.log(p1.name); // Praveen

Key points:

The function name usually starts with a capital letter.
The new keyword is used to call the constructor.
this refers to the new object being created.

1. Constructor in ES6 class (modern way):

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

const p1 = new Person("Praveen", 22);

Here:

constructor() is a special method inside a class.
It runs automatically when you create an object with new.

What happens when you use new?
When you do:

const p = new Person("Praveen", 22);

JavaScript:

Creates a new empty object
Sets this to that object
Runs the constructor function
Returns the object.

(TBD)

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