Foreclosure

Closure Exercise

1. Fork and clone this project.
2. Open the foreclosure.js file in your editor.
3. Run $ npm install to install all needed packages for this project.
4. Run $ npm test run the tests and have them continually watch for changes and re-run tests automatically.
5. Follow the instructions below, and every time you see this symbol an additional test should pass.

Strict Mode

Use strict mode for this exercise.

Initialize variables

A global variable named data is available to you. This variable is an object.

1. Declare a key named steve on the data object, with an value of null.
2. Declare a key named stevesLoan on the data object, with an value of null.
3. Declare a key named monthsUntilEvicted on the data object, with an initial value of 0.

loan()

Declare a function named loan() that takes 0 arguments

Write the following statements inside the loan() function block

1. Declare a variable named account using const, with an initial value being a literal object having the following properties and values:
   • key : borrowed, value : 550000
   • key : balance, value : 286000
   • key : monthlyPayment, value : 1700
   • key : defaulted, value : 0
   • key : defaultsToForeclose, value : 5
   • key : foreclosed, value : false
2. Declare a function named missPayment that takes 0 arguments.
   • Access the defaulted property of the account variable and increase it’s value by 1.
   • Write a conditional that, when the value of account.defaulted is greater than or equal to account.defaultsToForeclose, will run the following statement:
     • set the value of the foreclosed property of the account object to true
3. returns a literal object with the following properties:
   • key : getBalance, value : an unnamed function expression that takes 0 arguments.
     • Create a closure by returning the value of balance by accessing that property of the locally scoped variable account.
   • key : receivePayment, value : an unnamed function expression that takes 1 argument named amount.
     • Create a conditional statement that will run the following statements when amount is less than account.monthlyPayment :
       • invoke the missPayment function with 0 arguments
     • Finally, decrement the value of the balance property of the account variable, by the value of the amount parameter.
   • key : getMonthlyPayment, value : an unnamed function expression that takes 0 arguments.
     • Create a closure by returning the value of monthlyPayment by accessing that property of the locally scoped variable account.
   • key : isForeclosed, value : an unnamed function expression that takes 0 arguments.
     • Create a closure by returning the value of foreclosed by accessing that property of the locally scoped variable account.

borrower()

Declare a function named borrower() that takes 1 argument named loan

Write the following statements inside the borrower() function block

1. Declare a variable named account using const, with an initial value being a literal object having the following properties and values:
   • key : monthlyIncome, value : 1350
   • key : funds, value : 2800
   • key : loan, value : loan
2. returns a literal object with the following properties:
   • key : getFunds, value : an unnamed function expression that takes 0 arguments.
     • Create a closure by returning the value of funds by accessing that property of the locally scoped variable account.
   • key : makePayment, value : an unnamed function expression that takes 0 arguments.
     • Conditionally perform either block of statements
       • if account.funds is greater than the value of the loan’s monthly payment
         • decrement account.funds by the value of the loan’s monthly payment
         • invoke the loan’s receivePayment function, and pass in the value of the loan’s monthly payment
       • otherwise
         • invoke the loan’s receivePayment function, and pass in the value of the account‘s current funds
         • set the value of the funds property of account to 0
   • key : payDay, value : an unnamed function expression that takes 0 arguments.
     • Increase the value of the funds property of account by the value of the property monthlyIncome of account

Set variables and “step forward in time”

1. Invoke the loan function and assign it’s return value to the variable data.stevesLoan.
2. Invoke the borrower function passing in the argument data.stevesLoan and assign it’s return value to the variable data.steve.
3. Create a while loop that runs the following statement while data.stevesLoan is not foreclosed:
   • data.steve invokes payDay
   • data.steve invokes makePayment
   • increment data.monthsUntilEvicted by 1

Conclusion

All tests should be passing.
The value of monthsUntilEvicted should be 13.
You can tweak some of hardcoded private values such as loan account.monthlyPayment and borrower account.monthlyIncome a little to inspect the different possible outcomes. however, be careful! if the house never goes into foreclosure, you will encounter an endless loop.

Bonus

Adjust the while loop to also exit when the house has been paid off.

License

Copyright (c) 2015 Dev League. Licensed under the MIT license.