strlen doesn't work

Question

i was just make a simple script, but it don't work.

function check_length($string, $min_length, $max_length) {
  $length = strlen($string);
  if(strlen($length) < $min_length || strlen($length) > $max_length)
  { 
    header("Location: /kontakty/blad");
  }
}

check_length($_POST["name"], "3", "45");
check_length($_POST["surname"], "3", "45");
check_length($_POST["group_id"], "1", "11");

When i send data to script, the function don't check this.

Edit: I was do like You wrote and now script don't wanna redirect.

Full script

`$length = strlen($string);` you already calculated length so when you `strlen($length)` it calculate length of $length not string — NullPoiиteя, Feb 04 '13 at 13:39

score 8 · Accepted Answer · answered Feb 04 '13 at 13:27

8

You have a mistake. remove strlen on $length.

function check_length($string, $min_length, $max_length) {
      $length = strlen($string);

     if($length < $min_length || $length > $max_length)
     { 
      header("Location: /kontakty/blad");
     }
}

answered Feb 04 '13 at 13:27

Zevi Sternlicht

5,399
19
31

God: I was wrote script like You and the function don't check length. May i show You my full script: http://wklej.org/hash/4937e6cdeec/ – giertych97 Feb 04 '13 at 13:38
if should check length `die($string)` in function add check what you getting – NullPoiиteя Feb 04 '13 at 13:46
@RomanKonopski try removing the quotes around your numbers perhaps? Doubt that is the problem but you might as well rule it out! – Zevi Sternlicht Feb 04 '13 at 13:47
you are sending string not number @InGodITrust is right – NullPoiиteя Feb 04 '13 at 13:48

score 3 · Answer 2 · answered Feb 04 '13 at 13:51

3

Seems you use this script on an unicode'd site (kontakty) and suppose you need to use mb_strlen instead strlen for this work. Additionally, use trim, or "a " gives 2 length in this case.

function check_length($string, $min, $max) {
    $length = mb_strlen(trim($string), 'utf-8');
    if ($length < $min || $length > $max) { 
        header('Location: /kontakty/blad');
    }
}

If mb_strlen doesn't work for you, can use this:

function strlen_unicode($str) {
    return count(preg_split(
        '~~u', $str, -1, PREG_SPLIT_NO_EMPTY));
}

answered Feb 04 '13 at 13:51

Kerem

11,377
5
59
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do you know why my mb_strlen didn't working? i try in my local server and it's working but when I upload mb_strlen and strlen length is same. Please reply if you can. Really appreciate. – Scramble Aug 18 '15 at 09:11
@scramble; you should set internal encoding using `mb_internal_encoding` func at the first. – Kerem Aug 20 '15 at 11:51
Then why in my local server mb_strlen working well but in my hosting it doesn't work well? doesn't it because configuration in my local server? – Scramble Aug 24 '15 at 09:03

score 2 · Answer 3 · edited May 23 '17 at 12:29

function check_length($string, $min_length, $max_length) {

  $length = strlen($string);  <= calculated once

  if(strlen($length) < $min_length || strlen($length) > $max_length)
  ^^^^^^^^^^^^^                       ^^^^^^^
                                     no need of this it will calculate length of 
                                     $length no string   

  { 
    header("Location: /kontakty/blad");
  }
}

try

function check_length($string, $min_length, $max_length) {

  if(strlen($string) < $min_length || strlen($string) > $max_length)
  { 
    header("Location: /kontakty/blad");
  }
}

according to the code in your comment link

Note

The entire ext/mysql PHP extension, which provides all functions named with the prefix mysql_, is officially deprecated as of PHP v5.5.0 and will be removed in the future. So use either PDO or MySQLi

Good read

score 1 · Answer 4 · edited Feb 04 '13 at 13:36

1

Replace strlen($length) with $length in the line:

if(strlen($length) < $min_length || strlen($length) > $max_length)

You are taking the length of the length which make no sense.

edited Feb 04 '13 at 13:36

NullPoiиteя

56,591
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answered Feb 04 '13 at 13:27

MTilsted

5,425
9
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i thin it should be `strlen($string)` – NullPoiиteя Feb 04 '13 at 13:39

strlen doesn't work

4 Answers4

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