Codeigniter validation--how to limit numerical value?

You can use validation rule "greater_than[24]"

like for Example

$this->form_validation->set_rules('your_number_field', 'Your Number', 'numeric|required|greater_than[24]');

There's no maximum or minimum comparison function in the Form Validation Rule Reference, so you can just write your own validation function.

It's pretty straightforward. Something like this should work:

function maximumCheck($num){    if ($num > 24)    {        $this->form_validation->set_message(                        'your_number_field',                        'The %s field must be less than 24'                    );        return FALSE;    }    else    {        return TRUE;    }}$this->form_validation->set_rules(        'your_number_field', 'Your Number', 'callback_maximumCheck'    );

Sure you can, just make your own validation function and add it as a callback to validation rule. See http://codeigniter.com/user_guide/libraries/form_validation.html#callbacks

Hence, you will have

...$this->form_validation->set_rules('mynumber', 'This field', 'callback_numcheck');....function numcheck($in) {  if (intval($in) > 24) {   $this->form_validation->set_message('numcheck', 'Larger than 24');   return FALSE;  } else {   return TRUE;  }}