Javascript - Loop doesn't work correctly while performing a simulation

Question

I am trying to run a simulation of a library check in/out system with prototypes, objects and nested loops. I am having trouble properly integrating the pseudo code into the loop itself and would appreciate any help.

//while loop or for loop for 90 days
      //For loop over catalog
         //forloop over patrons 
             //Check if available , if so check book out
             //If not available check book back in
                 //check checking back in check to see if book is overdue and if so add a fine
    //When down loop over patrons to see their fees

Loop

for (var i = 0; i < 90; i++) {
        for (var j = 0; j < catalog.length; j++) {
            for (var k = 0; k < patrons.length; i++) {
                var fine = patrons[k].fine;
                if (catalog[k].Available) {
                    catalog[k].checkOut;
                } else {
                    catalog[k].checkIn;
                    patrons[k].read;
                }
                if (catalog[k].isOverdue) {
                    fine = fine + 5.00;
                }
            }
        }
        patrons[i].fine = fine;
    }

All the code

var Book = function(title, Available, publicationDate, checkoutDate, callNumber, Authors) {
    this.title = title;
    this.Available = Available;
    this.publicationDate = publicationDate;
    this.checkoutDate = checkoutDate;
    this.callNumber = callNumber;
    this.Authors = Authors;
};

var Author = function(firstName, lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
};

var Patron = function(firstName, lastName, libCardNum, booksOut, fine) {
    this.firstName = firstName;
    this.lastName = lastName;
    this.libCardNum = libCardNum;
    this.booksOut = booksOut;
    this.fine = fine;
};

Book.prototype.checkOut = function() {
    this.Available = false;
    var temp = new Date(1000000000);
    var date = new Date() - temp;
    var res = new Date(date);
    this.checkoutDate = res;
};

Book.prototype.checkIn = function() {
    this.Available = true;
};

Book.prototype.isOverdue = function() {
    var singleDay = 1000 * 60 * 60 * 24;
    var todayDate = new Date().getTime();
    var difference = todayDate - this.checkoutDate.getTime();
    if (Math.round(difference / singleDay) >= 14) {
        return true;
    }
    return false;
};

Patron.prototype.read = function(book) {
    this.booksOut.add(book);
}

Patron.prototype.return = function(book) {
    this.booksOut.remove(this.booksOut.length);
}

var authors = [];
authors[0] = new Author("Auth", "One");
authors[1] = new Author("AutL", "Two");

var catalog = [];
catalog[0] = new Book('Bk1', true, new Date(2001, 1, 21), new Date(), 123456, authors);
catalog[1] = new Book('Bk2', true, new Date(2002, 2, 22), new Date(), 987656, authors);
catalog[2] = new Book('Bk3', true, new Date(2003, 3, 23), new Date(), 092673, authors);
catalog[3] = new Book('Bk4', true, new Date(2004, 4, 24), new Date(), 658342, authors);
catalog[4] = new Book('Bk5', true, new Date(2005, 5, 25), new Date(), 345678, authors);

var patrons = [];
patrons[0] = new Patron('Pat1', 'Wat', 1, catalog, 0.00);
patrons[1] = new Patron('Pat2', 'Wot', 1, catalog, 0.00);
patrons[2] = new Patron('Pat3', 'Wit', 1, catalog, 0.00);
patrons[3] = new Patron('Pat4', 'Wet', 1, catalog, 0.00);
patrons[4] = new Patron('Pat5', 'Wut', 1, catalog, 0.00);

//while loop or for loop for 90 days
      //For loop over catalog
         //forloop over patrons 
             //Check if available , if so check book out
             //If not available check book back in
                 //check checking back in check to see if book is overdue and if so add a fine
    //When down loop over patrons to see their fees

for (var i = 0; i < 90; i++) {
    for (var j = 0; j < catalog.length; j++) {
        for (var k = 0; k < patrons.length; i++) {
            var fine = patrons[k].fine;
            if (catalog[k].Available) {
                catalog[k].checkOut;
            } else {
                catalog[k].checkIn;
                patrons[k].read;
            }
            if (catalog[k].isOverdue) {
                fine = fine + 5.00;
            }
        }
    }
    patrons[i].fine = fine;
}

for (i = 0; i < patrons.length; i++) {
    console.log(patrons[i].firstName + " has checked out the following books:");
    for (j = 0; j < patrons[i].booksOut.length; j++) {
        console.log(patrons[i].booksOut[j].title);
    }
    console.log(patrons[i].firstName + " has fine amount: $" + patrons[i].fine);
}

I am trying to write a loop that simulates checkouts and checkins for a 3 month period. Every day I iterate over the catalog, and every person in the patrons array. If the patron currently has the book checked out then I check it in. If it is not checked out then I add it to the patrons list of books via the patrons read method. If the book is overdue then I add a fine of $5.00 to the patron returning it. At the end of the 3 month period, I have to display each patron, the books they have currently checked out and any fine they may have.

Answer 1

you have typo error in your loops (for var k ... i++). See the snippet

var Book = function(title, Available, publicationDate, checkoutDate, callNumber, Authors) {
    this.title = title;
    this.Available = Available;
    this.publicationDate = publicationDate;
    this.checkoutDate = checkoutDate;
    this.callNumber = callNumber;
    this.Authors = Authors;
};

var Author = function(firstName, lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
};

var Patron = function(firstName, lastName, libCardNum, booksOut, fine) {
    this.firstName = firstName;
    this.lastName = lastName;
    this.libCardNum = libCardNum;
    this.booksOut = booksOut;
    this.fine = fine;
};

Book.prototype.checkOut = function() {
    this.Available = false;
    var temp = new Date(1000000000);
    var date = new Date() - temp;
    var res = new Date(date);
    this.checkoutDate = res;
};

Book.prototype.checkIn = function() {
    this.Available = true;
};

Book.prototype.isOverdue = function() {
    var singleDay = 1000 * 60 * 60 * 24;
    var todayDate = new Date().getTime();
    var difference = todayDate - this.checkoutDate.getTime();
    if (Math.round(difference / singleDay) >= 14) {
        return true;
    }
    return false;
};

Patron.prototype.read = function(book) {
    this.booksOut.add(book);
}

Patron.prototype.return = function(book) {
    this.booksOut.remove(this.booksOut.length);
}

var authors = [];
authors[0] = new Author("Auth", "One");
authors[1] = new Author("AutL", "Two");

var catalog = [];
catalog[0] = new Book('Bk1', true, new Date(2001, 1, 21), new Date(), 123456, authors);
catalog[1] = new Book('Bk2', true, new Date(2002, 2, 22), new Date(), 987656, authors);
catalog[2] = new Book('Bk3', true, new Date(2003, 3, 23), new Date(), 092673, authors);
catalog[3] = new Book('Bk4', true, new Date(2004, 4, 24), new Date(), 658342, authors);
catalog[4] = new Book('Bk5', true, new Date(2005, 5, 25), new Date(), 345678, authors);

var patrons = [];
patrons[0] = new Patron('Pat1', 'Wat', 1, catalog, 0.00);
patrons[1] = new Patron('Pat2', 'Wot', 1, catalog, 0.00);
patrons[2] = new Patron('Pat3', 'Wit', 1, catalog, 0.00);
patrons[3] = new Patron('Pat4', 'Wet', 1, catalog, 0.00);
patrons[4] = new Patron('Pat5', 'Wut', 1, catalog, 0.00);

//while loop or for loop for 90 days
      //For loop over catalog
         //forloop over patrons 
             //Check if available , if so check book out
             //If not available check book back in
                 //check checking back in check to see if book is overdue and if so add a fine
    //When down loop over patrons to see their fees

for (var i = 0; i < 90; i++) {
    for (var j = 0; j < catalog.length; j++) {
        for (var k = 0; k < patrons.length; k++) {
            var fine = patrons[k].fine;
            if (catalog[k].Available) {
                catalog[k].checkOut;
            } else {
                catalog[k].checkIn;
                patrons[k].read;
            }
            if (catalog[k].isOverdue) {
                fine = fine + 5.00;
            }
             patrons[k].fine = fine;
        }
    }
   
}

for (i = 0; i < patrons.length; i++) {
    console.log(patrons[i].firstName + " has checked out the following books:");
    for (j = 0; j < patrons[i].booksOut.length; j++) {
        console.log(patrons[i].booksOut[j].title);
    }
    console.log(patrons[i].firstName + " has fine amount: $" + patrons[i].fine);
}

Answer 2

May be this is gonna help

Keep in mind that they are asking for 3 months period or 90 days period. we can't just iterate 90 times. Eventually you will be ended up in the same month. For an example: if today is 10/19/2017 that means this program should calculate until 01/19/2018 (3 months period)

//***************** library.js *****************//


/**
 Create a constructor function for a Book object. The Book object should have the following properties:
  
 Title: string 
 Available: Boolean representing whether the book is checked out or not. The initial value should be false. 
 Publication Date: Use a date object
 Checkout Date: Use a date object 
 Call Number: Make one up 
 Authors: Should be an array of Author objects
**/
var Book = function(title, available, publicationDate, checkOutDate, callNumber, authors) {

 this.title = title;
 this.available = available;
 this.publicationDate = publicationDate;
 this.checkOutDate = checkOutDate;
 this.callNumber = callNumber;
 this.authors = authors;
}

/**
 Create a constructor function for an object called Author. It should have a property for the
  
 first name: string
 last name: string
**/
var Author = function(firstName, lastName) {

 this.firstName = firstName;
 this.lastName = lastName;
}

/**
 Create a constructor function for an object called Patron. This represents a person who is allowed to check out books from the library. Give it the following properties:

 Firstname: string
 Lastname: string
 Library Card Number (Make one up): string
 Books Out (make it an array): []
 fine (Starts a 0.00): parseFloat(0.00)
**/
var Patron = function(firstName, lastName, libraryCardNumber, booksOut, fine) {
 
  this.firstName = firstName;
  this.lastName = lastName;
  this.libraryCardNumber = libraryCardNumber;
  this.booksOut = booksOut;
  this.fine = parseFloat(fine) || 0.00;
}

// Methods
/**
Add a function to the Book prototype called "checkOut". The function will change the available property of the book from true to false and set the checkout date. The checkout date should be set to the current date minus some random number of days between 1 and 5. This will allow us to simulate books being overdue.
**/
Book.prototype.checkOut = function(date) {
  this.available = false;
 
  this.checkOutDate = new Date(date.setDate(date.getDate() - Math.floor((Math.random() * 5) + 1))); 
}

/**
Add a function to the Book prototype called "checkIn". The function will change the available property of the book from false to true.
**/
Book.prototype.checkIn = function() {
  this.available = true;
}

/**
Add a function called isOverdue that checks the current date and the checked out date and if it's greater than 5 days it returns true
**/
Book.prototype.isOverdue = function(date) {
 var time = date.getTime();
 var checkOutDate = (this.checkOutDate).getTime();
 var timeDiff = Math.abs(time - checkOutDate);
 var dayDiff = Math.ceil(timeDiff/ (1000 * 3600 * 24));
  
 if (dayDiff > 5) {
  return true;
 } else {
  return false;
 }
}

/**
Add a function called isCheckedOut that returns true if the book is checked out to someone and false if not.
**/
Book.prototype.isCheckedOut = function() {
 if (this.available === true) {
  return false;
 } else {
  return true;
 }
}

/**
Add a function to the Patron prototype called "read" that adds a book to it's books out property.
**/
Patron.prototype.read = function(book) {
 this.booksOut.push(book);
}

/**
Add a function to the Patron prototype called "return" that removes a book from it's books out property.
**/
Patron.prototype.return = function(book) {
 var booksOut = this.booksOut;
 booksOut.forEach(function(existingBook, index) {
  if (existingBook.title === book.title) {
   booksOut.splice(index, 1);
  }
 });
}

/**
Create 5 different books from the Book Class and store them in an array called catalog.
**/
var catalog = [];

catalog[0] = new Book('Another Brooklyn', false, new Date(2017, 5, 30), new Date(), '201-360-9955', [new Author('Jacqueline', 'Woodson')]);
catalog[1] = new Book('Sunshine State', false, new Date(2017, 4, 11), new Date(), '888-888-888', [new Author('Sarah', 'Gerard')]);
catalog[2] = new Book('Homegoing', false, new Date(2017, 5, 2), new Date(), '877-990-3321', [new Author('Yaa', 'Gyasi')]);
catalog[3] = new Book('Round Midnight', false, new Date(2015, 11, 22), new Date(), '321-221-2100', [new Author('Laura', 'McBride')]);
catalog[4] = new Book('The Sport of Kings', false, new Date('08/22/2016'), new Date(), '813-289-0007', [new Author('C.E.', 'Morgan')]);

/**
Create 5 different patrons from the Patron Class and store them in an array called patrons.
**/
var patrons = [];

patrons[0] = new Patron('Bhaumik', 'Mehta', 'Lib-229781', [catalog[0]], 0.00);
patrons[1] = new Patron('Jeff', 'Reddings', 'Lib-337895', [catalog[1]], 0.00);
patrons[2] = new Patron('Andrew', 'Hansing', 'Lib-227896', [catalog[2]], 0.00);
patrons[3] = new Patron('Dylan', 'Marks', 'Lib-672563', [catalog[3]], 0.00);
patrons[4] = new Patron('Roop', 'Kapur', 'Lib-008936', [catalog[4]], 0.00);


/**
Write a loop that simulates checkouts and checkins for a 3 month period. Every day iterate over each book in the catalog, and every person in the patrons array(Nested Loops). If the current book is not checked out and the current patron does not have a book already, then add it to the patrons list of books via the patrons read method and check it out by calling the books checkout method. If the book is checked out to the current person, then check if it is overdue, and if so, check it in using the books check in method, and return it using the patrons return method. When checking in, if the book is overdue then add a fine of $5.00 to the patron returning it. At the end of the 3 month period, display each patron, the books they have currently checked out and any fine they may have.
**/

var now = new Date();
var threeMonthsFromNow = new Date(now.setMonth(now.getMonth() + 3));
var timeDiff = Math.abs(threeMonthsFromNow.getTime() - new Date().getTime());
var days = Math.ceil(timeDiff/ (1000 * 3600 * 24));

for (var i = 0; i < days; i ++) {

    var date = new Date(new Date().setDate(new Date().getDate() + i));
   
    catalog.forEach(function(item, index) {
  
     patrons.forEach(function(patron, index) {

      if (item.isCheckedOut() === false) {
  
       var booksOut = (patron.booksOut).filter(function(book) {
        return book.title === item.title;
       });
   
       if (booksOut.length === 0) {
    
        patron.read(item);
        item.checkOut(date);
       }
  
      } else if (item.isCheckedOut() === true) {
  
       var booksOut = (patron.booksOut).filter(function(book) {
        return book.title === item.title;
       });
    
       if (booksOut.length > 0) {
    
        var isOverdue = item.isOverdue(date);
      
        if (isOverdue === true) {
      
         item.checkIn();
         patron.return(item);
         patron.fine += parseFloat(5.00);
        }
       }
      }
     });
    });
}

/**
Object with the method to execute the record list for patrons
**/
var records = {
 
 patronInfo: function() {
  
  patrons.forEach(function(patron, index) {

   console.log('Patron name: ' + patron.firstName + ' ' + patron.lastName);
   console.log('Patron library card number: ' + patron.libraryCardNumber);
   console.log('List of book(s) checked out currently by the patron:');

   if ((patron.booksOut).length === 0) {

    console.log('NO BOOKS ARE CHECKED OUT CURRENTLY');

   } else {

    (patron.booksOut).forEach(function(book, index) {

     console.log((index + 1) + '. | ' + book.title + ' | Checked out on: ' + (book.checkOutDate).toDateString());
    });
   }

   console.log('Patron ' + patron.firstName + ' ' + patron.lastName + ' has fine amout(till date): $' + (patron.fine).toFixed(2));
   console.log('-----------------------------------------------------');
  });
 }
};

/**
Method execution
**/
records.patronInfo();