[SOLVED] Verify input

[AV1611]

Easy one:

 

Sorry, but I can never get regex right...

 

I need to verify an input is

4 digits ONLY (not MORE or LESS)

numbers ONLY

must be greater than 0100

 

Thanks...

 

 

[StormTheGates]

Uhm how about this:

 

$length = strlen($input);
if($length != 4 OR $input < 100) {
     echo "Must be 4 chars and over 100!";
}

[AV1611]

What happens if they input "ABCD"?

 

[per1os]

You have two choices, www.php.net/REGEX or modifying the above example as so.

 

<?php
$length = strlen($input);
if(($length != 4 OR $input < 100) OR !is_numeric($input)) {
     echo "Must be 4 chars and over 100!";
}
?>

 

www.php.net/ereg

 

That is probably the better way to go is regex, but the above example should work too.

[redbullmarky]

would the addition of is_numeric help?

 

edit: beaten to it

[AV1611]

There are so many functions...

 

How do you guys remember all them?

 

This solves my problem, but I really need to find someone to help me with regex... after 2 years and 2 major web apps I still can't do them

 

 

[per1os]

I don't. Anytime I want something that I do not know if it exists or not I goto www.php.net and do a search.

 

For this one I searched for numeric.

 

Heck give it a try:

www.php.net

 

Search functions for numeric or number and see what comes up!

 

That is what I love about PHP the whole manual is online and easily searchable with real world examples and user contributions. There is no function that you should not be able to understand in PHP or be able to not find.

[StormTheGates]

if(ereg("[^[:digit:]]", $input)) {
      echo "Not a good amount!";
}

 

Makes sure its only numeric. However I think that

 

if(!ctype_digit($input)) {
      $error = "Not a good amount!";
}

 

Is better

[AV1611]

would

if(ereg("[^1-9]", $input))

be valid/correct?

[redbullmarky]

possibly:

 

$result = preg_match('/([0-9]{4})/', $input, $matches);

 

however it wouldnt determine if the number is at least 100...

 

edit added boundaries, as would have otherwise find ANY group of 4 numbers:

 

$result = preg_match('/^([0-9]{4})$/', $input, $matches);

[StormTheGates]

Do 0-9 instead. Otherwise 0 will be excluded

[redbullmarky]

had a quick play with it. not properly tested and very messy, but seems to work..?

 

<?php
$result = preg_match('/^(([0-9][1-9]|[1-9][0-9])[0-9]{2})$/', $input, $matches);
?>

 

which (i think) checks the first 2 digits to make sure that at least one of them is greater than 0 (1000 or 0100, for example)

 

seems to do everything you want.

[AV1611]

 

...    '/^  ...  $/'  ...

 

I snipped away all the part I understand.  What you have left is the syntax part, which is what I don't understand

 

'    ' <--- single quotes, as that's the string

/  / <--- why do I need those?

^    <--- what's that for?

$    <--- does that have something to do with the end of the string?

 

I've read it in the manual a dozen times, but I just can't "get it"

 

Thanks guys...

[redbullmarky]

/'s enclose the regex statement. the caret (^) signifies that we're looking from the start, the $ signifies the end of the string.

 

so in English, the regex says:

 

from the start of the string to the end, find 2 numbers that can't be both zero, as well as 2 further numbers. in all, find 4 numbers. (i think lol)

 

there's a board specifically for regex here - some of the posts/stickies may be of assistance. in my case, regex is very much about trial and error as opposed to actually knowing

[AV1611]

As always, You remain my hero Red  ;D

[redbullmarky]

moved here from PHP Help as some of the people round here might have a different take on things