我试图让我的嵌套循环执行签入/签出模拟。我有我的功能设置和我的循环结束但它总是给我相同的输出。每个赞助人拥有相同数量的书籍和大量的罚款，而不是像checkOut和isOverdue函数那样完全随机化。
如何使循环使用函数中随机生成的日期，并为每个顾客提供不同数量的罚款和不同的书籍？ Instructions for the project.
我的代码：
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;
};
function randInRange(start, end) {
return Math.floor(Math.random() * (end - start + 1)) + start;
}
Book.prototype.checkOut = function() {
this.Available = false;
var dateChk = new Date();
var randDay = randInRange(1, 25);
dateChk.setDate(dateChk.getDate() - randDay);
this.checkoutDate = dateChk;
};
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);
}
答案 0 :(得分：1)
我必须对您的示例进行一些更改，以便实际运行。
要知道的一件非常重要的事情是，当您调用对象的方法时，您必须将括号放在调用后面：不是catalog[j].checkOut而是catalog[j].checkOut()。
您可以检查我的更改以及脚本现在的工作方式。有了这个，您就可以制定后续问题。
希望这有帮助。
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;
};
function randInRange(start, end) {
return Math.floor(Math.random() * (end - start + 1)) + start;
}
Book.prototype.checkOut = function() {
this.Available = false;
var dateChk = new Date();
var randDay = randInRange(1, 25);
dateChk.setDate(dateChk.getDate() - randDay);
this.checkoutDate = dateChk;
};
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;
};
// Changed the read method
Patron.prototype.read = function(book) {
this.booksOut[book.callNumber] = book;
}
// Changed the return method
Patron.prototype.return = function(book) {
delete(this.booksOut[book.callNumber]);
}
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);
// Changed how Patrons are initialised. Instead of passing the full
// catalog for booksRead an empty object is passed.
var patrons = [];
patrons[0] = new Patron('Pat1', 'Wat', 1, {}, 0.00);
patrons[1] = new Patron('Pat2', 'Wot', 1, {}, 0.00);
patrons[2] = new Patron('Pat3', 'Wit', 1, {}, 0.00);
patrons[3] = new Patron('Pat4', 'Wet', 1, {}, 0.00);
patrons[4] = new Patron('Pat5', 'Wut', 1, {}, 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 < 3; i++) {
// changed the for loop
for (var j in catalog) {
// changed the for loop
for (var k in patrons) {
var fine = patrons[k].fine;
// Changed catalog[k] to catalog[j]
// moved and changed patrons[k].read() call
// added the patrons[k].return() call
if (catalog[j].Available) {
catalog[j].checkOut();
patrons[k].read(catalog[j]);
} else if (patrons[k].booksOut[catalog[j].callNumber]) {
catalog[j].checkIn();
patrons[k].return(catalog[j]);
}
if (catalog[j].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 in patrons[i].booksOut) {
console.log(patrons[i].booksOut[j].title);
}
console.log(patrons[i].firstName + " has fine amount: $" + patrons[i].fine);
}
修改
回答评论。
这是您设置for循环的结果。第一天所有的书都送到了第一个赞助人，第二天他们去了第二个partron，依此类推。
答案 1 :(得分：1)
在模拟过程中，说明书并未说明要对书籍或顾客进行洗牌，因此您的结果不会像您希望的那样随意。在书籍和顾客的循环中，我们可以使用标准forEach和常规for循环，使代码更容易遵循。我正在使用lodash _.shuffle在每个循环中随机化书籍和顾客以获得更好的结果。我们还可以通过简单的模拟隐藏我们的顾客返回原型中的精细逻辑。
for (var i = 0; i < 90; i++) {
_.shuffle(books).forEach(function(book) {
_.shuffle(patrons).forEach(function(patron) {
if (patron.hasBookCheckedOut(book)) {
return patron.return(book);
}
if (book.available) {
patron.read(book);
}
});
});
};