Couple field validation questions

[Mazer14]

Having trouble figuring this out.

 

1) How can I check whether the user's input for a field is an integer with a value greater than 0?

 

Was thinking of using regular expressions using 1-9 but then 10 might result in an error and that's not wanted.

 

2) For a field that's a drop-down, how can I have an error show if they choose the default option (value of "none")

 

Thanks for the help.

[MadLittleMods]

Should work but post back with any problems...

 

1)

if(preg_match('/([0-9]{1,})/', $thing_to_check))
{
     // GOOD
}
else
{
     // ERROR
}

 

2)

if(preg_match('/none/', $thing_to_check))
{
     // ERROR
}

[Mazer14]

Ahh, figured out #2 as you entered your reply

 

if($_POST['field'] == 'none')

 

Was what I had done.

 

I'll look at your post. Thanks man!

 

[Mazer14]

Cool, so I got those worked out.

 

One more question though. Trying to have an error occur when they leave a text field blank:

 

if (empty($_POST['name']) || $_POST['name'] == " " || $_POST['name'] == "  " || $_POST['name'] == "  ")

 

Is there a method to make an error occur any time a string of spaces are entered instead of having to do " " and "  " and "  " and so on?

[MadLittleMods]

try...

 

if(preg_match('/(\s]{0,})/', $thing_to_check))
{
     // GIVE THEM AN ERROR
}

[Pikachu2000]

There's no need to use a pattern for number 1.

 

if( is_numeric($_POST['value']) && intval($_POST['value']) > 0 ) {

// value validates

}

[/code]

[cyberRobot]

There's no need to use a pattern for number 1.

 

if( is_numeric($_POST['value']) && intval($_POST['value']) > 0 ) {

// value validates

}

[/code]

 

 

As long as you're ok with things like the following being considered a number:

+01.45

2.45

 

[cyberRobot]

Should work but post back with any problems...

 

1)

if(preg_match('/([0-9]{1,})/', $thing_to_check))
{
     // GOOD
}
else
{
     // ERROR
}

 

 

As is, the above regular expression will match anything that contains a number; including "a2". It should work however by changing it to:

 

<?php
...

if(preg_match('/^([0-9]{1,}$)/', $thing_to_check) && $thing_to_check > 0) {
     // GOOD

} else {
     // ERROR
}

...
?>

 

 

Note that I also added the secondary check to make sure it doesn't match 0.

[cyberRobot]

You could simplify the expression with the following:

 

<?php
...

if(preg_match("/^\d+$/", $thing_to_check) && $thing_to_check > 0) {
     // GOOD

} else {
     // ERROR
}

...
?>

[cyberRobot]

Cool, so I got those worked out.

 

One more question though. Trying to have an error occur when they leave a text field blank:

 

if (empty($_POST['name']) || $_POST['name'] == " " || $_POST['name'] == "  " || $_POST['name'] == "  ")

 

Is there a method to make an error occur any time a string of spaces are entered instead of having to do " " and "  " and "  " and so on?

 

You could trim the value before testing it:

 

<?php
...

$_POST['name'] = trim($_POST['name']);

...
?>

 

 

For more information about trim(), check out:

http://php.net/manual/en/function.trim.php

[Pikachu2000]

There's no need to use a pattern for number 1.

 

if( is_numeric($_POST['value']) && intval($_POST['value']) > 0 ) {
// value validates
}

 

 

 

As long as you're ok with things like the following being considered a number:

+01.45

2.45

 

 

I didn't mean is_numeric(); I never even use that myself. I meant ctype_digit() . . .

 

if( ctype_digit($_POST['value']) && intval($_POST['value']) > 0 ) {
// value validates
}

[cyberRobot]

I didn't mean is_numeric(); I never even use that myself. I meant ctype_digit() . . .

 

if( ctype_digit($_POST['value']) && intval($_POST['value']) > 0 ) {
// value validates
}

 

Nice, I've been wondering if there was an alternative to regular expressions. A lot of people suggest is_numeric().

 

ctype_digit() appears to be that answer.

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

 

 

Out of curiosity, why did you include intval()? The code seems to work fine without it. It doesn't throw any warnings either with

error_reporting(-1);

[Pikachu2000]

Just to make sure the integer value is greater than zero. It's one of those things I've been doing forever and can't seem to stop, but yes, it should work fine either way.

[cyberRobot]

Just to make sure the integer value is greater than zero. It's one of those things I've been doing forever and can't seem to stop, but yes, it should work fine either way.

 

Thanks for the info!