simple regular expression examples in PHP

1.10 digit contact number:

  if(preg_match("/^[0-9]{10}$/", "1234567880"))//contact no
  {
   echo 'okay';
  }else{
   echo 'denied';
  }
  
2. Email Address:

  if(preg_match("/^([a-zA-Z0-9_-]|\.)+@(([a-z0-9_-])+\.)+[a-z]{2,6}$/", "someone@domain .local"))//email
  {
   echo 'okay';
  }else{
   echo 'denied';
  }
  
3.names: 

  if(preg_match("/^[a-zA-Z]{2,30}$/", "KK"))//names
  {
   echo 'okay';
  }else{
   echo 'denied';
  }

4. Email validation 

$email = "someone@domain.local";

if(!filter_var($email, FILTER_VALIDATE_EMAIL)) {
    echo "E-mail is not valid";
} else {
    echo "E-mail is valid";
}

for more references

http://www.php.net/manual/en/function.preg-match.php
http://www.php.net/manual/en/function.filter-var.php

Adios!