ArrayList sorting on stronged typed objects

[JDeats]

If I have

class Student
{
public string LastName
public string FirstName
public int Age;
public int ID;
}

and I have an ArrayList that's storing only Student objects, how can I
sort the ArrayList by LastName? Using a IComparer class appears to only
allow < > comparisons on a numeric field...

 

[Guest]

Use IComparable.

Or even simpler, here's an article that will show you how to sort on
anything... or everything...

http://ianfnelson.com/blog/archive/2006/02/27/UniversalComparer.aspx

Dale

 

[Cor Ligthert [MVP]]

JDeats,

You investigated already the power of the DataTable Class, it is completely
build in, so very cheap to use and can used to be inherited and than
completely strongly typed.

Cor

 

[Jon Skeet [C# MVP]]

If I have

class Student
{
public string LastName
public string FirstName
public int Age;
public int ID;
}

and I have an ArrayList that's storing only Student objects, how can I
sort the ArrayList by LastName? Using a IComparer class appears to only
allow < > comparisons on a numeric field...

No, IComparer is the way to go here - just return the value of
x.LastName.CompareTo(y.LastName);

 

[Otis Mukinfus]

If I have

class Student
{
public string LastName
public string FirstName
public int Age;
public int ID;
}

and I have an ArrayList that's storing only Student objects, how can I
sort the ArrayList by LastName? Using a IComparer class appears to only
allow < > comparisons on a numeric field...

Have a look at this:

http://www.otismukinfus.com/vault/vault.htm


Good luck with your project,

Otis Mukinfus
http://www.arltex.com
http://www.tomchilders.com

 

[Guest]

Actually, CompareTo() is defined in IComparable. IComparer defines Compare().
--
Dale Preston
MCAD C#
MCSE, MCDBA

 

[Jon Skeet [C# MVP]]

Actually, CompareTo() is defined in IComparable. IComparer defines
Compare().

Indeed - but I was suggesting calling String.CompareTo when
implementing Compare.