email validation

[arkadia93]

Does anybody have an email validation script in Javascript?

 

[DotNetGnat]

function validateEmail( strValue) {
var objRegExp  =
 /(^[a-z]([a-z_\.]*)@([a-z_\.]*)([.][a-z]{3})$)|(^[a-z]([a-z_\.]*)@
  ([a-z_\.]*)(\.[a-z]{3})(\.[a-z]{2})*$)/i;

  //check for valid email
  return objRegExp.test(strValue);
}

-DNG

 

[kss444]

/*==========================================================
Function: validateEmail
Purpose: Make sure email is valid
==========================================================*/
function validateEmail (vEmail) {
/* The following pattern is used to check if the entered e-mail address
fits the user@domain format. It also is used to separate the username
from the domain. */
var emailPat=/^(.+)@(.+)$/
/* The following string represents the pattern for matching all special
characters. We don't want to allow special characters in the address.
These characters include ( ) < > @ , ; : \ " . [ ] */
var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"
/* The following string represents the range of characters allowed in a
username or domainname. It really states which chars aren't allowed. */
var validChars="\[^\\s" + specialChars + "\]"
/* The following pattern applies if the "user" is a quoted string (in
which case, there are no rules about which characters are allowed
and which aren't; anything goes). E.g. "jiminy cricket"@disney.com
is a legal e-mail address. */
var quotedUser="(\"[^\"]*\")"
/* The following pattern applies for domains that are IP addresses,
rather than symbolic names. E.g. joe@[123.124.233.4] is a legal
e-mail address. NOTE: The square brackets are required. */
var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/
/* The following string represents an atom (basically a series of
non-special characters.) */
var atom=validChars + '+'
/* The following string represents one word in the typical username.
For example, in john.doe@somewhere.com, john and doe are words.
Basically, a word is either an atom or quoted string. */
var word="(" + atom + "|" + quotedUser + ")"
// The following pattern describes the structure of the user
var userPat=new RegExp("^" + word + "(\\." + word + ")*$")
/* The following pattern describes the structure of a normal symbolic
domain, as opposed to ipDomainPat, shown above. */
var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")


/* Finally, let's start trying to figure out if the supplied address is
valid. */

/* Begin with the coarse pattern to simply break up user@domain into
different pieces that are easy to analyze. */
var matchArray=vEmail.match(emailPat)
if (matchArray==null) {
/* Too many/few @'s or something; basically, this address doesn't
even fit the general mould of a valid e-mail address. */
alert("Email address seems incorrect (check @ and .'s)")
return false
}
var user=matchArray[1]
var domain=matchArray[2]

// See if "user" is valid
if (user.match(userPat)==null) {
// user is not valid
alert("The username doesn't seem to be valid.")
return false
}

/* if the e-mail address is at an IP address (as opposed to a symbolic
host name) make sure the IP address is valid. */
var IPArray=domain.match(ipDomainPat)
if (IPArray!=null) {
// this is an IP address
for (var i=1;i<=4;i++) {
if (IPArray>255) {
alert("Destination IP address is invalid!")
return false
}
}
return true
}

// Domain is symbolic name
var domainArray=domain.match(domainPat)
if (domainArray==null) {
alert("The domain name doesn't seem to be valid.\n Please check spelling and spacing.")
return false
}

/* domain name seems valid, but now make sure that it ends in a
three-letter word (like com, edu, gov) or a two-letter word,
representing country (uk, nl), and that there's a hostname preceding
the domain or country. */

/* Now we need to break up the domain to get a count of how many atoms
it consists of. */
var atomPat=new RegExp(atom,"g")
var domArr=domain.match(atomPat)
var len=domArr.length
if (domArr[domArr.length-1].length<2 ||
domArr[domArr.length-1].length>3) {
// the address must end in a two letter or three letter word.
alert("The address must end in a three-letter domain, or two letter country.")
return false
}

// Make sure there's a host name preceding the domain.
if (len<2) {
var errStr="This address is missing a hostname!"
alert(errStr)
return false
}

// If we've gotten this far, everything's valid!
return true;
}

 

[johnwm]

kss444
If you want to post someone else's code its polite just to post a link rather than copying/pasting as if it was yours! Your post seems to be copied straight from

http://p2p.wrox.com/topic.asp?TOPIC_ID=26712

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[onpnt]

On top of that I know we all don't have time to post long winded explanations but..

/(^[a-z]([a-z_\.]*)@([a-z_\.]*)([.][a-z]{3})$)|(^[a-z]([a-z_\.]*)@
([a-z_\.]*)(\.[a-z]{3})(\.[a-z]{2})*$)/i;

That requires some explanation. Sense the question was so general I would imagine that won't help much but cause hell later on if they don't know what and how

Just a thought

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