Email validation PHP Script

Last updated on January 4th, 2022 at 11:48 am

The below function will valide the email address,

Function to validate email address in PHP

function validateEmail($email)
{
   if(eregi('^[a-zA-Z0-9._-]+@[a-zA-Z0-9-]+\.[a-zA-Z]{2,4}(\.[a-zA-Z]{2,3})?(\.[a-zA-Z]{2,3})?$', $email))
      return true;
   else
      return false;
}


Detailed explanation of the regex above.
^[a-zA-Z0-9._-]+@[a-zA-Z0-9-]+\.[a-zA-Z]{2,4}(\.[a-zA-Z]{2,3})?(\.[a-zA-Z]{2,3})?$
The ^ sign represents the beginning of the string.
[a-zA-Z0-9._-]
a-z Matches character range “a” to “z”

A-Z Matches character range “A” to “Z”

0-9 Matches character range “0” to “9”

. Matches character “.”

_ Matches character “_”

– Matches character “-”
+
Match one of more preceding charecter
@
Matches a character @
[a-zA-Z0-9-]
a-z Matches character range “a” to “z”

A-Z Matches character range “A” to “Z”

0-9 Matches character range “0” to “9”

– Matches character –
+
Match one of more preceding charecter
\.
Escape character, Matches character “.”
[a-zA-Z]
a-z Matches character range “a” to “z”

A-Z Matches character range “A” to “Z”
{2,3}
Matches between 2 and 4 preceding charecter
?
Matches between 0 and 1 preceding charecter
Group 1
\.
Escape character, Matches character “.”
[a-zA-Z]{2,3}
Matches any character range “a” to “z” (Case Sensitive) between 2 and 3
Group 2
Same as group 1 above.
Note: The last part(Group) is optional when you have an email with domain for example [email protected] or something