Find Uppercase words in a String using C#

I am helping a friend to build an Editor API in C#. One of the functionalities in the Editor is to filter uppercase words in a string and highlight them. Here’s a sample of how uppercase words can be filtered in a string

static void Main(string[] args)
// code from
var strwords = FilterWords("THIS is A very STRANGE string");
foreach (string str in strwords)

static IEnumerable<string> FilterWords(string str)
var upper = str.Split(' ')
.Where(s => String.Equals(s, s.ToUpper(),

return upper;


The code shown above is quite simple. The FilterWords method accepts a string, uses the Split() function to split the string into a string array based on a space delimiter and finally compares each string to its upper case. All the matches are then returned to the caller function.


Uppercase string filter

About The Author

Suprotim Agarwal
Suprotim Agarwal, Developer Technologies MVP (Microsoft Most Valuable Professional) is the founder and contributor for DevCurry, DotNetCurry and SQLServerCurry. He is the Chief Editor of a Developer Magazine called DNC Magazine. He has also authored two Books - 51 Recipes using jQuery with ASP.NET Controls. and The Absolutely Awesome jQuery CookBook.

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1 comment:

Dinesh Chrysler said...

good article.

another similar piece of code with simplicity,
string l5 = "INDIA is a small COUNTRY";
var output5 = l5.Split(' ').Where(x => x == x.ToUpper());
string output6 = output5.Aggregate((item1, item2) => item1 + " " + item2);