Date format validation in PHP

Validate a date in “YYYY-MM-DD” format.

function checkDateFormat($date)
{
    //match the format of the date
    if (preg_match ("/^([0-9]{4})-([0-9]{2})-([0-9]{2})$/", $date, $parts))
    {
        //check weather the date is valid of not
        if(checkdate($parts[2],$parts[3],$parts[1]))
            return true;
        else
        return false;
    }
    else
        return false;
}

Parsing XML in easy way using PHP

Required Extension: SimpleXML

//this is a sample xml string
$xml_string="<?xml version='1.0'?>
<moleculedb>
    <molecule name='Benzine'>
        <symbol>ben</symbol>
        <code>A</code>
    </molecule>
    <molecule name='Water'>
        <symbol>h2o</symbol>
        <code>K</code>
    </molecule>
</moleculedb>";
 
//load the xml string using simplexml function
$xml = simplexml_load_string($xml_string);
 
//loop through the each node of molecule
foreach ($xml->molecule as $record)
{
   //attribute are accessted by
   echo $record['name'], '  ';
   //node are accessted by -> operator
   echo $record->symbol, '  ';
   echo $record->code, '<br />';
}

Email validation snippet in PHP

$email = $_POST['email'];
if(preg_match("~([a-zA-Z0-9!#$%&amp;'*+-/=?^_`{|}~])@([a-zA-Z0-9-]).([a-zA-Z0-9]{2,4})~",$email)) {
    echo 'This is a valid email.';
} else{
    echo 'This is an invalid email.';
}