freeCodeCamp/guide/english/javascript/tutorials/construct-javascript-objects-with-functions/index.md

title
Construct JavaScript Objects with Functions

Using constructors it is easy to create new objects using a blueprint or constructor. The declaration syntax is a little different but still easy to remember.

// Let's add the properties engines and seats to the car in the same way that the property wheels has been added below. They should both be numbers.
var Car = function() {
  this.wheels = 4;
  this.engines = 1;
  this.seats = 1;
};

var myCar = new Car();

The name of a constructor function usually begins with a capital letter (unlike other functions, which tend to begin with a lowercase character). The uppercase letter is supposed to help remind developers to use the new keyword when they create an object using that function.