We can perform an email validation through this function.<\/p>\n
\tfunction isValidEmail($email){\r\n\t\treturn eregi('^[_a-z0-9-]+(\\.[_a-z0-9-]+)*@[a-z0-9-]+(\\.[a-z0-9-]+)*(\\.[a-z]{2,3})$', $email);\r\n\t}\r\n<\/pre>\nAfter fainted for a few seconds when i saw unreal4u finding, i decided to throw up preg_match solution instead.<\/p>\n
\tfunction isValidEmail($email){\r\n\t\treturn preg_match('\/^[_a-z0-9-]+(\\.[_a-z0-9-]+)*@[a-z0-9-]+(\\.[a-z0-9-]+)*(\\.[a-z]{2,3})$\/i', $email);\r\n\t}\r\n<\/pre>\nPHP 5.2 and above.<\/p>\n
function fnValidateEmail($email)\r\n{\r\n return filter_var($email, FILTER_VALIDATE_EMAIL);\r\n}\r\n<\/pre>\nSanitize Email<\/h2>\n
We can further sanitize our email to ensure that everything is alright.<\/p>\n
function fnSanitizeEmaill($string) {\r\n return preg_replace( '((?:\\n|\\r|\\t|%0A|%0D|%08|%09)+)i' , '', $string );\r\n}\r\n<\/pre>\nPHP 5.2 and above.<\/p>\n
function fnSanitizeEmaill($url)\r\n{\r\n return filter_var($url, FILTER_SANITIZE_EMAIL);\r\n}\r\n<\/pre>\nValidate Email Exist<\/h2>\n
This is not possible but certain validation can be use to validate email existence<\/a>.<\/p>\nfunction check_email($email)\r\n{\r\n\t$email_error = false;\r\n\t$Email = htmlspecialchars(stripslashes(strip_tags(trim($email)))); \/\/parse unnecessary characters to prevent exploits\r\n\tif ($Email == '') { email_error = true; }\r\n\telseif (!eregi('^([a-zA-Z0-9._-])+@([a-zA-Z0-9._-])+\\.([a-zA-Z0-9._-])([a-zA-Z0-9._-])+', $Email)) { email_error = true; }\r\n\telse {\r\n\tlist($Email, $domain) = split('@', $Email, 2);\r\n\t\tif (! checkdnsrr($domain, 'MX')) { email_error = true; }\r\n\t\telse {\r\n\t\t$array = array($Email, $domain);\r\n\t\t$Email = implode('@', $array);\r\n\t\t}\r\n\t}\r\n\r\n\tif (email_error) { return false; } else{return true;}\r\n}\r\n<\/pre>\nValidate Number Only<\/h2>\n
We can use PHP built-in function to validate whether a given value is a number.<\/p>\n
function fnValidateNumber($value)\r\n{\r\n\t#is_ double($value);\r\n\t#is_ float($value);\r\n\t#is_ int($value);\r\n\t#is_ integer($value);\r\n\treturn is_numeric($value);\r\n}\r\n<\/pre>\nPHP 5.2 and above.<\/p>\n
function fnValidateNumber($value)\r\n{\r\n\t#return filter_var($value, FILTER_VALIDATE_FLOAT); \/\/ float\r\n\treturn filter_var($value, FILTER_VALIDATE_INT); # int\r\n}\r\n<\/pre>\nSanitize Number<\/h2>\n
We can force all value to be only numeric by sanitize them.<\/p>\n
function fnSanitizeNumber($str)\r\n{\r\n\t#letters and space only\r\n\treturn preg_match('\/[^0-9]\/', '', $str);\r\n}\r\n<\/pre>\nPHP 5.2 and above.<\/p>\n
function fnSanitizeNumber($value)\r\n{\r\n\t#return filter_var($value, FILTER_SANITIZE_NUMBER_FLOAT); \/\/ float\r\n\treturn filter_var($value, FILTER_SANITIZE_NUMBER_INT); # int\r\n}\r\n<\/pre>\nValidate String Only<\/h2>\n
Sometimes to validate name we can use this function to restrict only letters and spaces.<\/p>\n
function fnValidateStringr($str)\r\n{\r\n\t#letters and space only\r\n\treturn preg_match('\/^[A-Za-z\\s ]+$\/', $str);\r\n}\r\n<\/pre>\nSanitize String<\/h2>\n
We can sanitize it instead of validate user input.<\/p>\n
function fnSanitizeStringr($str)\r\n{\r\n\t#letters and space only\r\n\treturn preg_replace('\/[^A-Za-z\\s ]\/', '', $str);\r\n}\r\n<\/pre>\nPHP 5.2 and above. built-in function by PHP provides a much more powerful sanitize capability.<\/p>\n
function fnSanitizeStringr($str)\r\n{\r\n\treturn filter_var($str, FILTER_SANITIZE_STRIPPED); # only 'String' is allowed eg. '<br>HELLO<\/br>' => 'HELLO'\r\n}\r\n<\/pre>\nValidate Alphanumeric Characters<\/h2>\n
This validates alphanumeric characters.<\/p>\n
function fnValidateAlphanumeric($string)\r\n{\r\n\treturn ctype_alnum ($string);\r\n}\r\n<\/pre>\nSanitize Alphanumeric Characters<\/h2>\n
This sanitize alphanumeric characters. eg. \u201cHELLO! Do we have 90 idiots running around here?\u201d => \u201cHELLO Do we have 90 idiots running around here\u201d<\/p>\n
function fnSanitizeAlphanumeric($string)\r\n{\r\n\treturn preg_replace('\/[^a-zA-Z0-9]\/', '', $string);\r\n}\r\n<\/pre>\nValidate URL Exist<\/h2>\n