I am trying to sort a string split by comma. But it is not behaving as expected
var classes = "10,7,8,9";
Console.Write(string.Join(",", classes.Split(',').OrderBy(x => x)));
Console.ReadKey();
and output is
10,7,8,9
But I want the expected output to be like:
7,8,9,10
Classes can have a section along with them. like 7a,7b
and I want to achieve it on one line of code.
You can use Regex like this
var classes = "10,7,8,9";
Regex number = new Regex(@"^\d+");
Console.Write(string.Join(",", classes.Split(',').OrderBy(x => Convert.ToInt32(number.Match(x).Value)).ThenBy(x => number.Replace(x, ""))));
Console.ReadKey();
CODE:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using System.Collections;
namespace Rextester
{
public class Program
{
public static void Main(string[] args)
{
var l = new List<string> { "1D", "25B", "30A", "9C" };
l.Sort((b, a) =>
{
var x = int.Parse(Regex.Replace(a, "[^0-9]", ""));
var y = int.Parse(Regex.Replace(b, "[^0-9]", ""));
if (x != y) return y - x;
return -1 * string.Compare(a, b);
});
foreach (var item in l) Console.WriteLine(item);
}
}
}
OUTPUT: 1D 9C 25B 30A
ONLINE COMPILE: http://rextester.com/CKKQK66159
Use the following using-directive:
using System.Text.RegularExpressions;
And try the following:
var input = "7,7a,8,9a,9c,9d,10";
var sorted = from sp in input.Split(',')
let reg = Regex.Match(sp, @"(?<num>[0-9]+)(?<char>[a-z]*)", RegexOptions.IgnoreCase | RegexOptions.Compiled)
let number = int.Parse(reg.Groups["num"].ToString())
orderby reg.Groups["char"].ToString() ascending // sort first by letter
orderby number ascending // then by number
select sp;
var result = string.Join(",", sorted);
Console.WriteLine(result);
//output (tested): 7,7a,8,9a,9c,9d,10
It uses regex to determine the numeric and alphabetic part of the input string.
The regex pattern uses named groups, which are noted as follows: (?<group_name> regex_expr ).
O(n log(n)), in case you are worried about big collections of numbers.
orderby-clause.
All on one line, also supports '4a' etc.
edit: On testing this, a string such as 1,2,111,3 would display as 111,1,2,3, so may not quite be what you're looking for.
string str = "1,2,3,4a,4b,5,6,4c";
str.Split(',').OrderBy(x => x).ToList().ForEach(x=> Console.WriteLine(x));
Console.ReadKey();
Here is my implementation:
IEnumerable<Tuple<string, string[]>> splittedItems =
items.Select(i => new Tuple<string, string[]>(i, Regex.Split(i, "([0-9]+)")));
List<string> orderedItems = splittedItems.OrderBy(t => Convert.ToInt16(t.Item2[1]))
.ThenBy(t => t.Item2.Length > 1 ? t.Item2[2] : "1")
.Select(t => t.Item1).ToList();
The result is like required: { "10", "7", "8b", "8a", "9" } is sorted to { "7", "8a", "8b", "9", "10" }
You are sorting strings (alphabetically), so yes, "10" comes before "7".
My solution converts "10,7b,8,7a,9b" to "7a,7b,8,9b,10" (first sort by the integer prefix, then by the substring itself).
Auxiliary method to parse the prefix of a string:
private static int IntPrefix(string s)
=> s
.TakeWhile(ch => ch >= '0' && ch <= '9')
.Aggregate(0, (a, c) => 10 * a + (c - '0'));
Sorting the substrings by the integer prefix then by the string itself:
classes.Split(',') // string[]
.Select(s => new { s, i = IntPrefix(s) }) // IEnumerable<{ s: string, i: int }>
.OrderBy(si => si.i) // IEnumerable<{ s: string, i: int }>
.ThenBy(si => si.s) // IEnumerable<{ s: string, i: int }>
.Select(si => si.s) // IEnumerable<string>
One liner (with string.Join):
var result = string.Join(",", classes.Split(',').Select(s => new {s, i = IntPrefix(s)}).OrderBy(si => si.i).ThenBy(si => si.s).Select(si => si.s));
