How to iterate through a list and edit is content?

Question

var courses = _repository.GetAllCoursesDetailsByCourseId(id);
var result = (from s in courses select new {  id = s.Course_ID,  name=s.Course_Date}).Distinct().ToList();

Now what i want to do is to iterate through result and edit all of its "name" content . . a rough idea is below :

foreach (var i in result)
{
     string[] temp = i.name.Split(',');
     string[] token = temp[0].Split(' ');
     string newtemp = token[1] + " " + temp[1];
     i.name = newtemp;
}

But this is not working. How can i edit the content in var result?

Could you elaborate about what is not working ? Do you get an error ? Results elements not changed after the foreach ? — Omri Aharon, Apr 16 '14 at 07:43
it underlines i.name and says Readonly property cannot be used as assignment target — ZaraQ, Apr 16 '14 at 07:44
http://msdn.microsoft.com/en-us/library/zshzt6s3(v=vs.90).aspx — ray, Apr 16 '14 at 07:45
http://msdn.microsoft.com/en-us/library/zshzt6s3(v=vs.90).aspx — ray, Apr 16 '14 at 07:47
Then how you modify Readonly properties. Change it read/write. — Muhammad Umar, Apr 16 '14 at 07:48

score 0 · Answer 1 · answered Apr 16 '14 at 07:44

0

Try something like this:

foreach (var i in result)
{
 string temp = i.name.Split(',');
 string token = temp.Split(' ');
 string newtemp = token + " " + temp;
 i.name = newtemp;
 }

answered Apr 16 '14 at 07:44

Ni3

489
3
12

score 0 · Answer 2 · edited May 23 '17 at 11:56

0

Anonymous objects are immutable, that's why you're getting the Readonly error message.

I suggest you look here for some more information: Why are the properties of anonymous types in C# read-only?

edited May 23 '17 at 11:56

Community

1
1

answered Apr 16 '14 at 07:51

Omri Aharon

16,959
5
40
58

score 0 · Answer 3 · answered Apr 16 '14 at 07:52

Anonymous type properties are readonly.

Build a function that does the name generation and then use it directly in the LINQ:

private string GenerateNewName(string name) {
    string temp = name.Split(',');
    string token = temp.Split(' ');
    return token + " " + temp;
}

var result = (from s in courses select new {  id = s.Course_ID,  name=GenerateNewName(s.Course_Date)}).Distinct().ToList();

score 0 · Answer 4 · answered Apr 16 '14 at 07:52

This should fix your problem. (I didn't change your code, but you should be careful with your index, if you didn't found any ',' or ' ' you will throw an exception)

var result = (from s in courses select new {  id = s.Course_ID,  name= splitName(s.Course_Date) }).Distinct().ToList();

private string splitName(string value)
{
     string[] temp = i.name.Split(',');
     string[] token = temp[0].Split(' ');
     return (token[1] + " " + temp[1]);
}

score 0 · Answer 5 · answered Apr 16 '14 at 07:57

0

When you use foreach ,whatever changes you do, the changes are in the temp var i, not in the actual list, try using the traditonal for or an iterator.

answered Apr 16 '14 at 07:57

Adwait

290
2
11

score 0 · Answer 6 · answered Apr 16 '14 at 08:07

As @Muhammad said, you need another list with updated values. You can extend your list search through Where extension method on any list, then apply your changes like below,

var newResult = result.Where(q=> q.name == "ValueToUpdate").ToList().ForEach(i => i.name = "NewValue");

How to iterate through a list and edit is content?

6 Answers6