Defining a object's methods inside the object itself means that a new instance of the function is created for each instantiation of the object, bloating the instances. 


Instead, it is more efficient to define the functions outside the object using the ``++prototype++`` keyword. This yields a single instance of each function, to which all the objects of that type refer.

== Noncompliant Code Example

----
function Person(firstName, middleInitial, lastName) {
  this.firstName = firstName;
  this.middleInitial = middleInitial;
  this.lastName = lastName;

  this.nameReversed = function() {  // Noncompliant
    return this.lastName + ", " + this.firstName + " " + this.middleInitial;
  }
}
----

== Compliant Solution

----
function Person(firstName, middleInitial, lastName) {
  this.firstName = firstName;
  this.middleInitial = middleInitial;
  this.lastName = lastName;
}

Person.prototype.nameReversed = function() {
  return this.lastName + ", " + this.firstName + " " + this.middleInitial;
}
----