- Posted by Shay Friedman on February 3, 2012
I love programming languages. I think they are beautiful. One of the best things about learning different programming languages is finding the different approaches and techniques of each language. This also allows you to incorporate them into other programming languages. One of my favorite languages is Ruby, and Rubyists have this habit of writing meaningful code in one line, AKA “one liner”. C#-ers don’t do one-liners very much, probably because they couldn’t write cool one-liners till not so long ago.
BUT! this has all changed with the arrival of LINQ. The first time you see it you go “WHAT THE ****!?!?!?##@@!??!??”, then you go “hmmmmm” and eventually you have a silly happy look on your face and it seems like everything you can pronounce is “wow” and “cool!”. That’s why my nickname for LINQ is “CDD” – Coolness Driven Development.
So for this post I’ve gathered some cool C# one-liners that I’ve put together with the help of LINQ and features of the C# language. Have more? add a comment!
Filter lists
var list = new List<string>() {"Asia", "Africa", "North America", "South America", "Antartica", "Europe", "Australia"};
// Get all the items from the list that start with
// an 'A' and have 'r' as the 3rd character
var filteredList = list.Where(item => item.StartsWith("A")).Where(item => item[2] == 'u').ToList();
Create a new list from the first items of another list
// Take the first 3 items from list 'list' and create a new list with them
var shortList = list.Take(3).ToList();
Remove duplicate items from a list
var listWithoutDuplicates = list.Distinct().ToList();
Print all items in a list
list.ForEach(Console.WriteLine);
Cool string counting stuff
var str = "H1e2l3l4l5o6";
// Count all digits in a string
var numOfDigits = str.Count(char.IsDigit);
// Count all lowercase characters in a string
var numOfLowerCase = str.Count(char.IsLower);
// Count all uppercase characters within a string
var numOfUpperCase = str.Count(char.IsUpper);
Comparing two lists
var list = new List<string>() { "Asia", "Africa", "North America", "South America", "Antartica", "Europe", "Australia" };
var list2 = new List<string> {"Africa", "South America", "Antartica", "Foo"};
// Get all items in the list that do NOT have matching items on a different list
var list3 = list.Except(list2).ToList();
// Get all items in the list that have matching items on a different list
list3 = list.Intersect(list2).ToList();Convert all items in a list
string[] numbersAsText = new[] {"1", "2", "3"};
int[] numbers = numbersAsText.Select(n => Convert.ToInt32(n)).ToArray();
numbers.ToList().ForEach(Console.WriteLine);
Do heavy processing of parts of groups in threads
var nums = Enumerable.Range(1, 100);
Parallel.ForEach(nums.GroupBy(num => num%2), numGroup => DoHeavyStuff(numGroup.ToList()));
Well, that’s what I have… I bet there are tons more. Go ahead C#-ers, it’s your time to shine!
Shay.