php validate integer

问题:

I`m wonder why this not working

    echo gettype($_GET['id']); //returns string   if(is_int($_GET['id']))   {    echo 'Integer';   } 

How to validate data passing from GET/POST if it is integer ?

回答1:

The manual says:

To test if a variable is a number or a numeric string (such as form input, which is always a string), you must use is_numeric().

Alternative you can use the regex based test as:

if(preg_match('/^\d+$/',$_GET['id'])) {   // valid input. } else {   // invalid input. } 

回答2:

Can use

$validatedValue = filter_input(INPUT_GET, 'id', FILTER_VALIDATE_INT); 

See http://php.net/filter_input and related functions.

回答3:

What about intval?

$int = intval($_GET['id']); 

回答4:

To validate form data (string) as an integer, you should use ctype_digit() It returns TRUE if every character in the string text is a decimal digit, FALSE otherwise. (PHP 4 >= 4.0.4, PHP 5)

Reference: http://php.net/manual/en/function.ctype-digit.php

回答5:

It sounds like you are checking if a string contains an integer, rather than if that variable is an integer. If so, you should check out php's regex (regular expression) functionality. It allows you to check for very specific patterns in a string to validate it for whatever criteria. (such as if it contains only number characters)

Here's the php page http://php.net/manual/en/function.preg-match.php

and here's a cheat sheet on regular expressions (to make the $pattern string) http://regexpr.com/cheatsheet/

回答6:

Try:

if(isNumeric($_GET['id'])) {     $cast_int = (int)$_GET['id']; }  if(isset($cast_int)) {     echo gettype($cast_int)."
\n";     if(is_int($cast_int))     {         echo 'Integer'."
\n";     } } else {     echo gettype($_GET['id'])." was passed
\n"; }  function isNumeric($numeric) {     return preg_match("/^[0-9]+$/", $numeric); } 

回答7:

I take a slightly more paranoid approach to sanitizing GET input

function sanitize_int($integer, $min='', $max='') {   $int = intval($integer);   if((($min != '') && ($int  $max)))     return FALSE;   return $int; } 

To be even safer, you can extract only numbers first and then run the function above

function sanitize_paranoid_string($string, $min='', $max='') {   $string = preg_replace("/[^a-zA-Z0-9]/", "", $string);   $len = strlen($string);   if((($min != '') && ($len  $max)))     return FALSE;   return $string; } 

Code from: http://libox.net

文章来源: php validate integer