how to declare an object javascript code example

Example 1: objects in javascript

let car = {
  engineNumber: 1234
  brand: 'BMW',
  break: function (){}
}

Example 2: how to create object js

function person(fname, lname, age, eyecolor){
  this.firstname = fname;
  this.lastname = lname;
  this.age = age;
  this.eyecolor = eyecolor;
}

myFather = new person("John", "Doe", 50, "blue");
document.write(myFather.firstname + " is " + myFather.age + " years old.");