On October 23rd, 2014, we updated our
By continuing to use LinkedIn’s SlideShare service, you agree to the revised terms, so please take a few minutes to review them.
Validation is the process of checking data against a
standard or requirement.
The term is commonly used when:
Checking the information entered by a person when
storing data, sending information or using an online
service (FORM VALIDATION).
Email Validation means to validate
and check an email address.
Is a email validator, which
Validates an Email Address
Check the grammar and syntax
Can be used in Data Entry forms and
C# Programming Language is
used for the development of this
WinForm and Regular Expressions
class is also used
What is a
Valid Email Address?
Valid Email Address
There's only one real answer to this:
A valid email address is one that you can send emails to
Contemporary email addresses consist of a "local part"
separated from a "domain part" (a fully-qualified domain
name) by an at-sign ("@").
Mymail@mycompany.com is a valid Email Address
If you only want to check if an address is grammatically
correct then you could use a regular expression
Using a regular expression that recognizes email addresses
could be useful in various situations:
to scan for email addresses in a document,
to validate user input,
or as an integrity constraint on a data repository.
Regular expressions are a very cool feature for
pattern recognition in strings.
Mathematically speaking regular expressions are
parsed through a "finite state machine".
As the name implies, such a machine has only a
finite number of states, and it has no external
Parsing or syntactic analysis is the process of
analysing a string of symbols, either in natural
language or in computer languages,
according to the rules of a formal grammar.
Regular Expression Processor
A regular expression processor processes a regular
expression statement expressed in terms of a
grammar in a given formal language, and with
that examines the target text string, parsing it to
identify substrings that are members of its
language, the regular expressions.
Regular Expression for Email Validation
Myname@mycompany.com can be validated as
We compared the given email address with the upper RegEx to validate it is synthetically
correct or not.
Any validation problems that involve
recursion, option, limitation is easier
to solve with regular expressions than
using other ways (like if-else if-else,
Regular Expressions can be used to
Test if a string matches some pattern.
Scan for virus signatures.
Process natural language.
Search for information using Google.
Search for markers in human genome
Search-and-replace in a word processors.
Validate data-entry fields (dates, email, URL, credit card)
Email Address Standards
There are acknowledged standards for what constitutes a valid
These are defined in the Request For Comments documents (RFCs)
The syntax of email addresses has been defined in various RFCs,
most notably RFC 822 and RFC 5322.
We u s e d R F C 5 3 2 2 , a s t h i s i s t h e l a t e s t s t a n d a r d .