how to do email verification in regex code example

Example 1: regex pattern to validate email

[a-zA-Z0-9._-]{3,}@[a-zA-Z0-9.-]{3,}\.[a-zA-Z]{2,4}

Example 2: how write a email validation regex

//Author: Mohammad Arman Khan
//Regular Expresssion for e-mail validation
var email_validator_regex = /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$/;

Example 3: regex validate email

# Language: Perl

sub Validate_Email($)
{
   my $sEmail = $_[0];
   my $sRetMsg = "";

   my $sUserNmRegex = "^[[:alnum:]]+([.!#\$\%&'*+-\/=?^_'{|]?[[:alnum:]]+)*";
   my $sDomainRegex = "@[[:alnum:]]+([.-]{1}[[:alnum:]]+)*";
   my $sEndRegex = "([.]{1}[[:alnum:]]+)+";

   #  Work
   #--------#

   if ($sEmail =~ /$sUserNmRegex$sDomainRegex$sEndRegex$/) {
      $sRetMsg = "Email is valid";
   }
   else {
      $sRetMsg = "Email is not valid";
   }

   return $sRetMsg;
}

my $sEmail = '[email protected]';
print "[Email:$sEmail] : " . Validate_Email($sEmail) . "\n";

# OUTPUT -> [Email:[email protected]] : Email is valid