this_5.js

var customer = {
  firstName: "John",
  lastName: "Doe",
  greetCustomer: function(){
    console.log("Hello again " + this.firstName + " " + this.lastName + "!");
  },
  calculateAge: function(currentYear, birthDate){
       console.log(this.firstName + " is " + (currentYear - birthDate) + " years old.");
  }
}
var customer3 = {
  firstName: "Robert",
  lastName: "Mills"
}
// bind returns a new ageOfCustomer3 with a 'this' that now refers to obj customer3
var ageOfCustomer3 = customer.calculateAge.bind(customer3);
ageOfCustomer3(2016, 1978); // Prints Robert is 38 years old."