A constructor is a special function that creates and initializes an object instance of a class.
In JavaScript, a constructor gets called when an object is created using the new keyword.
The purpose of a constructor is to create a new object and set values for any existing object properties.
In a constructor function this does not have a value.
example:
class Polygon {
constructor() {
this.name = 'Polygon';
} }
const poly1 = new Polygon();
console.log(poly1.name); // expected output: "Polygon"
A constructor enables you to provide any custom initialization that must be done before any other methods can be called on an instantiated object.