ThenBy

In this chapter you will learn:

How to use ThenBy operator
Concatenate two ThenBy operators
ThenBy by custom Comparer

Get to know ThenBy operator

using System;//from  j a v  a2s  .co  m
using System.Collections;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        string[] names = { "Java", "C#", "Javascript", "SQL", 
              "Oracle", "Python", "C++", "C", "HTML", "CSS" };


        IEnumerable<string> query = names.OrderBy(s => s.Length).ThenBy(s => s);

        foreach (String s in query)
        {
           Console.WriteLine(s);
        }
    }
}

The output:

Concatenate two ThenBy operators

The following sorts first by length, then by the second character, and finally by the first character.

using System;//from   ja  v  a 2  s . c  o m
using System.Collections;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        string[] names = { "Java", "C#", "Javascript", "SQL", 
                "Oracle", "Python", "C++", "C", "HTML", "CSS" };

        names.OrderBy(s => s.Length).ThenBy(s => s[1]).ThenBy(s => s[0]);

        foreach (String s in names)
        {
           Console.WriteLine(s);
        }
    }
}

The output:

ThenBy by custom Comparer

Using an OrderBy and a ThenBy clause with a custom comparer to sort first by word length and then by a case-insensitive descending sort of the words in an array.

using System;//from   ja v  a2 s  .c om
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class CaseInsensitiveComparer : IComparer<string> {
    public int Compare(string x, string y) {
        return string.Compare(x, y, true);
    }
}

public class MainClass {
    public static void Main() {

        string[] words = { "a", "A", "b", "B", "C", "c" };

        var sortedWords =
            words.OrderBy(a => a.Length)
                    .ThenBy(a => a, new CaseInsensitiveComparer());

        foreach (var s in sortedWords) {
            Console.WriteLine(s);
        }
    }
}

Next chapter...

What you will learn in the next chapter: