Sort a field with in a 2D Array

Question

First I have 2 classes class Student { int StudentID string Name Fee fee } class Fees { int FeeID string FeeName DateTime FeeDueDate } let say there are 10 students objects Student[] stud = new Student[10] and if stud[0] has 4 fees ( Fee[4] ) and they are FeeID = 1  FeeName = Books  FeeDueDate = 2014/06/25 FeeID = 2  FeeName = Tuition  FeeDueDate = 2013/03/21 FeeID = 3  FeeName = Sports Equipment  FeeDueDate = 2013/03/18 FeeID = 4  FeeName = School Dorm  FeeDueDate = 2013/07/26 while stud[1] has 2 fees ( Fee[2] ) and they are FeeID = 2  FeeName = Books  FeeDueDate = 2014/06/20 FeeID = 4  FeeName = School Dorm  FeeDueDate = 2013/03/26 and stud[2] has ...... I need the sort the second collection which is the Fee by FeeDueDate asscending while Keep the same order of student so after sorting would be stud [ 0 ] => FeeID = 3  FeeName = Sports Equipment  FeeDueDate = 2013/03/18 FeeID = 2  FeeName = Tuition  FeeDueDate = 2013/03/21 FeeID = 4  FeeName = School Dorm  FeeDueDate = 2013/07/26 FeeID = 1  FeeName = Books  FeeDueDate = 2014/06/25 stud [ 1 ] => FeeID = 4  FeeName = School Dorm  FeeDueDate = 2013/03/26 FeeID = 2  FeeName = Books  FeeDueDate = 2014/06/20 How can this be done? Thanks Also this image shows my collections of objects http://oi50.tinypic.com/wuq9o3.jpg

Vulpes · Answer

OK so you don't want to sort the students themselves but you do want to sort their fees by ascending order of due date. In that case try this: foreach(Student stu in objStudentWithFeeData) { stu.Fees = stu.Fees.OrderBy(fee => fee.Duedate).ToArray(); }

Vulpes · Answer

Off the top of my head I'd try: objStudentWithFeeData = objStudentWithFeeData.OrderByDescending(stu => stu.Fees.Sum(fee => fee.FeeAmount)).ToArray();

David Chen · Answer

But now I am having another problem if Fee has another properties called FeeAmount now I need to sort the students collection BY the max fee amounted added together how is it this done I have been working on this forever my brains hurts with 2 dimensional stuff > if stud[0] has 2 fees ( Fee[2] ) and they are FeeID = 1  FeeAmount = 54.23 FeeID = 2  FeeAmount = 234.98 if stud[1] has 1 fees ( Fee[1] ) and they are FeeID = 1  FeeAmount = 9.99 if stud[2] has 3 fees ( Fee[3] ) and they are FeeID = 1  FeeAmount = 123.45 FeeID = 2  FeeAmount = 67.89 FeeID = 3  FeeAmount = 987.65 I need to sort the Student Collections by TotalAmount(Fee Collection) TotalAmount of Fee stud [ 0 ] = 54.23 + 234.98 = 289.21 stud [ 1 ] = = 9  99 stud [ 2 ] = 123.45 + 67.89 + 987.65 = 1178.99 there for after sorted it should become stud [ 0 ] = 123.45 + 67.89 + 987.65 = 1178.99 stud [ 1 ] = 54.23 + 234.98 = 289.21 stud [ 2 ] = = 9  99

David Chen · Answer

Yes! I figure it out too my solution is pretty muh the same as yours foreach (var student in objStudentWithFeeData) { student.Fees = student.Fees.OrderBy(c => c.DueDate).ToArray(); }

David Chen · Answer

Your solution seems to be working and I understand it I just updated the question as I was using an example but when I apply objStudentWithFeeData = objStudentWithFeeData.OrderBy(stu => stu.Fees.DueDate).ToList(); there is an error here: stu => stu.Fees.DueDate it cant find DueDate in stu.Fees. you can see my collections here http://oi50.tinypic.com/wuq9o3.jpg

Vulpes · Answer

I'd use a LINQ query for something like this. Here's an example: using System; using System.Collections.Generic; using System.Linq; class Baby { public string Name; public Birth Birthy; } class Birth { public string BirthCity; public string HospitalName; public DateTime Birthday; } class Test { static void Main() { Birth by1 = new Birth(); by1.Birthday = new DateTime(2013 2 1); Baby b1 = new Baby(); b1.Name = Freddy; b1.Birthy = by1; Birth by2 = new Birth(); by2.Birthday = new DateTime(2013 3 1); Baby b2 = new Baby(); b2.Name = Violet; b2.Birthy = by2; Birth by3 = new Birth(); by3.Birthday = new DateTime(2013 1 1); Baby b3 = new Baby(); b3.Name = Daniel; b3.Birthy = by3; List babies = new List {b1 b2 b3}; babies = babies.OrderBy(baby => baby.Birthy.Birthday).ToList(); foreach(Baby b in babies) { Console.WriteLine({0} : {1} b.Name b.Birthy.Birthday.ToString(MM/dd/yyyy)); } Console.ReadKey(); } } The output should be: Daniel : 01/01/2013 Freddy : 02/01/2013 Violet : 03/01/2013