Common Csharp dotnet Format specifiers or Format Strings for display

Name	Format String	Example	Comments
Currency Format	C or c or C2 - precision	Console.WriteLine(amount.ToString("C"))	output depends on your current UI culture
Percent Format	P or p or P2 - precision)	Console.WriteLine(number.ToString("P"))	output depends on your current UI culture
Padding with leading zero Format	0	var input = "123"; Console.WriteLine(input.ToString("0000")); //result will be 0123	Replaces the zero placeholder with the corresponding digit if one is present; otherwise, zero appears in the result string.
Long date Format with no time and zone info just verbose date	D	var date = DateTime.Now; Console.WriteLine(date.ToString("D"));	result will be Sunday,October 30,2015 (output depends on your current UI culture)
Short date Format with no time and zone info just date	d	var date = DateTime.Now; Console.WriteLine(date.ToString("d"));	result will be 10/30/2015 (output depends on your current UI culture)
Full date and time Format with no zone info	f or g	var date = DateTime.Now; Console.WriteLine(date.ToString("f"));	result will be Sunday,October 30,2015 12:23 PM (output depends on your current UI culture)
Just time Format	t or T	var date = DateTime.Now; Console.WriteLine(date.ToString("t"));	result will be 1:23 PM or 1:23:45 PM
Year month Format	Y or y	var date = DateTime.Now; Console.WriteLine(date.ToString("y"));	October, 2015
Month day Format	M or m	var date = DateTime.Now; Console.WriteLine(date.ToString("M"));	October 30 (output depends on UI culture)
UTC time Format	O or o	var date = DateTime.Now; Console.WriteLine(date.ToString("O"));	2015-10-30T13:45:30.0000000-07:00
Custom date and time Format	MMMM dd, yyyy	var date = DateTime.Now; Console.WriteLine(date.ToString("MMMM dd, yyyy"));	October 30, 2015
Custom date and time Format	MM/dd/yy H:mm:ss	var date = DateTime.Now;Console.WriteLine(date.ToString("MM/dd/yy H:mm:ss"));	10/30/15 14:14:11
Custom Format	d or dd - day of the month ddd or dddd - abbreviated or full day of the week M or MM - month of year MMM or MMMM - abbreviated month or full name of the month y or yy - two digit year YYYY - four digit year	var date = DateTime.Now; Console.WriteLine(date.ToString("d MMMM YYYY"));	30 October 2015
Enumeration Format strings	G or g	Console.WriteLine(LogLevel.Verbose.ToString("G")));	Displays enum entry as a string value. Here result will be Verbose
Enumeration Format strings	G or g or F or f	Console.WriteLine(LogLevel.Verbose.ToString("G")));	Displays enum entry as a string value. Here result will be Verbose
Enumeration Format strings	D or d	Console.WriteLine(LogLevel.Verbose.ToString("D")));	Displays enum entry as a integer value. Here result will be 1

Common Csharp dotnet Regex expressions for user input validation

Name	Pattern	Example
US zip code regex	^\d{5}(?:[-\s]\d{4})?$	12345 or 12345-2345
Canadian zip code regex	^([ABCEGHJKLMNPRSTVXY]\d[ABCEGHJKLMNPRSTVWXYZ])\ {0,1}(\d[ABCEGHJKLMNPRSTVWXYZ]\d)$	M4B 1B4
US phone number regex	\(?\d{3}\)?-? *\d{3}-? *-?\d{4}	(123) 345-234
US Date (MM/dd/YYYY) regex	^(0?[1-9]|[12][0-9]|3[01])[\/](0?[1-9]|1[012])[\/]\d{4}$	05/31/2016
24 Hour time regex	^(?:0?[0-9]|1[0-9]|2[0-3]):[0-5][0-9]$	13:12
12 Hour time regex (AM/PM)	^(([0]?[0-9]|1[0-2]):[0-5][0-9][ ][aApP][mM])|((1[3-9]|2[0-3]):[0-5][0-9])$	7:00 AM
Url regex	^(https?:\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w \.-]*)*\/?$	http://www.test.com or www.test.com
IP address regex	^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$	127.0.0.1
US social security number rgex	^([0-9]{3}[-]*[0-9]{2}[-]*[0-9]{4})*$	123-09-2345