Regex not working for password? not sure why - php

Question

So I have a regex code to make sure the password is from 4 to 13 characters, it keeps failing
public function valid_password($password){
if(preg_match('^.{3,14}^', $password)){
return true;
}//end if
else{
return false;
}//end else
}
I'm using regex and not php's length attribute because I will be adding more regex code later on. However, now I'm stuck with this failing program.
The problem is, it makes sure the password is over 3 characters however it doesn't care how long it is as if I have set no limit.
Thanks in advance

Answer 1

You have used ^ as delimiters php.net/mregexp.reference.delimiters.php here:
^.{3,14}^
That's possible, but not a good idea in your case, because you need the ^ for its actual purpose. It matches the start of the subject normally. And to correctly count the length, yout need to do that. You also need the $ end of subject meta character.
So basically:
preg_match('/^.{3,14}$/'
Now if you want to combine this regex with other match criteria, I would recommend this fancy assertion syntax:
preg_match('/(?=^.{3,14}$) (...)/x', $password)
This will allow you to specify something else in place of ... - and keep the length check implicit.

Answer 2

^ is the anchor for the beginning of a string. The end of a string is delimited using $:
public function valid_password($password) {
return preg_match('~^.{3,14}$~', $password);
}
But in this case I wouldn't use a regex, but the strlen function instead:
public function valid_password($password) {
$length = strlen($password);
return $length >= 3 && $length <= 14;
}
If you like hacking around to save you that line:
public function valid_password($password) {
return isset($password[2]) && !isset($password[14]);
}
But really, why do you want to restrict password length to 14 characters? That way you prevent people from choosing really secure passwords. You probably should raise that limit.

Answer 3

Try this:
preg_match('/^.{3,14}$/', $password)

Answer 4

try
preg_match('/^.{3,14}$/', $password)
but regexp for counting string length?? = Overkill

Answer 5

^ matches the start of a string, not the end. $ matches the end.
And you forgot your delimiters.
The full, fixed line is:
if (preg_match('/^.{3,14}$/', $password)) {
However, I strongly recommend that you instead use:
$len = strlen($password);
if ($len >= 3 && $len <= 14) {
instead, since regular expressions are completely overkill for this.