Pass a value into filter_input() using variable

Question

Can anyone please explain, why do I get very strange warning:

filter_input() expects parameter 1 to be long, string given

when executing the code, that is part of my class and which seems perfectly fine:

public static function Input($type, $data, $filter = 'FILTER_SANITIZE_SPECIAL_CHARS')
  {
    $type = 'INPUT_' . $type;
    return filter_input($type, $data, $filter);
  }

In case I change it to, for example:

return filter_input(INPUT_POST, $data, $filter);

Then the warning goes to:

filter_input() expects parameter 3 to be long.

Everything works just fine if I use:

return filter_input(INPUT_POST, $data, FILTER_SANITIZE_SPECIAL_CHARS);

I realize that on PHP: filter_input - Manual in description it's stated:

Description

mixed filter_input ( int $type , string $variable_name [, int $filter = FILTER_DEFAULT [, mixed $options ]] )

Parameters

type
   One of INPUT_GET, INPUT_POST, INPUT_COOKIE, INPUT_SERVER, or INPUT_ENV.

Questions:

Why it's said in manual filter_input ( int $type , - when neither INPUT_GET nor INPUT_POST and etc are INTEGERS.
Is there a way to pass a value into filter_input using variable?

deceze · Accepted Answer · 2014-01-08 12:43:41Z

7

What you're supposed to use there are constants. These constants have integer values. So the documentation is entirely correct, INPUT_GET is an integer. Try var_dump(INPUT_GET).

If you need to get a constant value from a string, use constant():

echo constant('INPUT_' . $type);

answered Jan 8, 2014 at 12:43

deceze♦

525k89 gold badges806 silver badges954 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Ilia Ross Over a year ago

Yes, so easy and straight-forward!! Never heard of that before!! It works as expected! Thank you!

sergio · Accepted Answer · 2014-01-08 12:48:03Z

1

Here the problem. When you concatenate 'INPUT_' with variable it bacame a string, see example:

echo $type = 'INPUT_' . 'POST'; // give you a string INPUT_POST

echo INPUT_POST; //give you 0

That's why :

filter_input() expects parameter 1 to be long, string given

answered Jan 8, 2014 at 12:48

sergio

5,2607 gold badges27 silver badges47 bronze badges

3 Comments

Ilia Ross Over a year ago

sergio, thanks but I'm not sure what you have meant!

sergio Over a year ago

When you do this: $type = 'INPUT_' . $type; it became a string, but not a constant like INPUT_POST.

Ilia Ross Over a year ago

Ah, alright! Yeah, deceze already explained that! +1 for an extra example!

Rico Sonntag · Accepted Answer · 2014-01-08 12:43:18Z

0

INPUT_POST and INPUT_GET are defined as follows:

/**
 * POST variables.
 * @link http://www.php.net/manual/en/filter.constants.php
 */
define ('INPUT_POST', 0);

/**
 * GET variables.
 * @link http://www.php.net/manual/en/filter.constants.php
 */
define ('INPUT_GET', 1);

answered Jan 8, 2014 at 12:43

Rico Sonntag

1,5181 gold badge15 silver badges23 bronze badges

2 Comments

Ilia Ross Over a year ago

Thank you, Rico! Could you please elaborate your answer, please!

Rico Sonntag Over a year ago

See @deceze answer for a final solution. I only wanted to point out the type of the constants.

Collectives™ on Stack Overflow

Pass a value into filter_input() using variable

Questions:

3 Answers 3

1 Comment

3 Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

Questions:

3 Answers 3

1 Comment

3 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related