Challenge: Solution Review

function HomeLoan(amount,duration){
  this.amount = amount
  this.interest = 0.08
  this.duration = duration
  this.calculateInterest = function(){
    return this.amount*this.interest*this.duration
  }
}
function StudentLoan(amount,duration){
  this.amount = amount
  this.interest = 0.03
  this.duration = duration
  this.calculateInterest = function(){
    return this.amount*this.interest*this.duration
  }
}
function PersonalLoan(amount,duration){
  this.amount = amount
  this.interest = 0.05
  this.duration = duration
  this.calculateInterest = function(){
    return this.amount*this.interest*this.duration
  }
}
function Loans(){
  this.getloan = function(type,amount,duration){
    var loan;
    switch(type){
      case 'home':
        loan = new HomeLoan(amount,duration)
        break;
      case 'student':
        loan = new StudentLoan(amount,duration)
        break;
      case 'personal':
        loan = new PersonalLoan(amount,duration)
        break;
      default :
        loan = null
        break;
    }
    return loan
  }
}
var loan = new Loans()
 
var homeLoan = loan.getloan('home',3200,5)
console.log(homeLoan.calculateInterest())
 
var studentLoan = loan.getloan('student',1800,4)
console.log(studentLoan.calculateInterest())
 
var personalLoan = loan.getloan('personal',1200,2)
console.log(personalLoan.calculateInterest())