js oop

//Defining object 
let person = { 
    first_name:'Mukul', 
    last_name: 'Latiyan', 
  
    //method 
    getFunction : function(){ 
        return (`The name of the person is  
          ${person.first_name} ${person.last_name}`) 
    }, 
    //object within object 
    phone_number : { 
        mobile:'12345', 
        landline:'6789'
    } 
} 
console.log(person.getFunction());  
console.log(person.phone_number.landline); 

let names = {
    fname: "Dillion",
    lname: "Megida"
}
console.log(names.fname);
console.log(names.hasOwnProperty("mname"));
// Expected Output
// Dillion
// false

function Person(name) {
  this.name = name;
  this.greeting = function() {
    alert('Hi! I\'m ' + this.name + '.');
  };
}

var salva = createNewPerson('Salva');
salva.name;
salva.greeting();

function createNewPerson(name) {
  var obj = {};
  obj.name = name;
  obj.greeting = function() {
    alert('Hi! I\'m ' + this.name + '.');
  };
  return obj;
}