10 C# One Liners to Impress Your Friends

oneliners.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Xml.Linq;

class TenCSharpOneLiners
{
    static void Main()
    {
        Print("Multiple each item in a list by 2", Enumerable.Range(1, 10).Select(i => i * 2));
        Print("Sum a list of numbers", Enumerable.Range(1, 1000).Sum());

        var wordlist = new[] { "C#", "and stuff" };
        var tweet = "This is an example tweet talking about C# and stuff";
        Print("Verify if a word exists in string", wordlist.Any(word => tweet.IndexOf(word) > -1));
        Print("Show matched words in string", wordlist.Where(word => tweet.IndexOf(word) > -1));

        Print("Read in a File", File.ReadAllBytes("oneliners.exe").Length);

        Print("Happy Birthday", Enumerable.Range(1, 4).Select((i) => string.Format("Happy Birthday {0} ", i == 3 ? "dear NAME" : "to You")));

        var passed = new List<int>();
        var failed = new List<int>();

        (from bucket in new[] { passed, failed } from i in new[] { 49, 58, 76, 82, 88, 90 } select new { bucket, i }).ToList().ForEach((tuple) => tuple.bucket.AddRange(Enumerable.Repeat(tuple, 1).Where((tup) => (tup.bucket == passed && tup.i > 60) || (tup.bucket == failed && tup.i <= 60)).Select((tup) => tup.i)));
        Print("Filter list of numbers >60", (IEnumerable<int>)passed);
        Print("Filter list of numbers <=60", (IEnumerable<int>)failed);

        Print("Fetch and Parse an XML web service", XDocument.Load("http://search.twitter.com/search.atom?&q=scala"));

        Print("Find minimum in a list", Enumerable.Min(new[] { 14, 35, -7, 46, 98 }));
        Print("Find maximum in a list", Enumerable.Max(new[] { 14, 35, -7, 46, 98 }));

        Print("Parallel Processing", Enumerable.Range(1, 10).AsParallel().Select((i)=>i*2).AsEnumerable());

        Print("Sieve of Eratosthenes", "TODO");

        Print("Fizzbuzz", Enumerable.Range(1, 15).Select((i)=>i + (i%3==0?"fizz":"") + (i%5==0?"buzz":"")));
    }

    static void Print<T>(string desc, T scalar)
    {
        Console.WriteLine("\n" + desc);
        Print(scalar);
    }

    static void Print<T>(T scalar)
    {
        Console.WriteLine(scalar);
    }

    static void Print<T>(string desc, IEnumerable<T> seq)
    {
        Console.WriteLine("\n" + desc);

        foreach (var item in seq)
        {
            Print(item);
        }
    }
}

except these are not all one line?

Nice! Some ideas:

• Instead of tweet.IndexOf(word) > -1 you can use the shorter tweet.Contains(word).
• File.ReadAllBytes("...").Length needs to be able to open the file to get its length, in such cases new FileInfo("...").Length may help.
• The passed/failed filtering can be made more readable: var (passed, failed) = (new[] { 49, 58, 76, 82, 88, 90 }).Aggregate((new List<int>(), new List<int>()), (l, x) => { (x > 60 ? l.Item1 : l.Item2).Add(x); return l; });
• Min. and max. can be called this way: (new[] { 14, 35, -7, 46, 98 }).Min() and (new[] { 14, 35, -7, 46, 98 }).Max().

The true One-Liner:

using System;using System.Collections.Generic;using System.IO;using System.Linq;using System.Xml.Linq;class TenCSharpOneLiners{static void Main(){Print("Multiple each item in a list by 2",Enumerable.Range(1,10).Select(i=>i*2));Print("Sum a list of numbers",Enumerable.Range(1,1000).Sum());var wordlist=new[]{"C#","and stuff"};var tweet="This is an example tweet talking about C# and stuff";Print("Verify if a word exists in string",wordlist.Any(word=>tweet.IndexOf(word)>-1));Print("Show matched words in string",wordlist.Where(word=>tweet.IndexOf(word)>-1));Print("Read in a File",File.ReadAllBytes("oneliners.exe").Length);Print("Happy Birthday",Enumerable.Range(1,4).Select((i)=>string.Format("Happy Birthday {0} ",i==3?"dear NAME":"to You")));var passed=new List<int>();var failed=new List<int>();(from bucket in new[]{passed,failed}from i in new[]{49,58,76,82,88,90}select new{bucket,i}).ToList().ForEach((tuple)=>tuple.bucket.AddRange(Enumerable.Repeat(tuple,1).Where((tup)=>(tup.bucket==passed&&tup.i>60)||(tup.bucket==failed&&tup.i<=60)).Select((tup)=>tup.i)));Print("Filter list of numbers >60",(IEnumerable<int>)passed);Print("Filter list of numbers <=60",(IEnumerable<int>)failed);Print("Fetch and Parse an XML web service",XDocument.Load("http://search.twitter.com/search.atom?&q=scala"));Print("Find minimum in a list",Enumerable.Min(new[]{14,35,-7,46,98}));Print("Find maximum in a list",Enumerable.Max(new[]{14,35,-7,46,98}));Print("Parallel Processing",Enumerable.Range(1,10).AsParallel().Select((i)=>i*2).AsEnumerable());Print("Sieve of Eratosthenes","TODO");Print("Fizzbuzz",Enumerable.Range(1,15).Select((i)=>i+(i%3==0?"fizz":"")+(i%5==0?"buzz":"")));}static void Print<T>(string desc,T scalar){Console.WriteLine("\n"+desc);Print(scalar);}static void Print<T>(T scalar){Console.WriteLine(scalar);}static void Print<T>(string desc,IEnumerable<T>seq){Console.WriteLine("\n"+desc);foreach(var item in seq){Print(item);}}}

(just minified your code, every c# program can be a oneliner... ;) )

The minifier I used: CSharpMinifier