Check if input number is valid in Codeigniter Form Validation

Question

Can you help me to validate if my input number is valid.

It can be a whole number It can also be a decimal number but interval is 0.5, So 0.5, 1.5 , 2.5 is ok but .2,1.3,2.6 is not valid.

if ((preg_match('/^\d+\.\d+$/',$bkpoints))  || (preg_match('/^\.\d+$/',$bkpoints)))
{       {
    if ($bkpoints % 0.5 !== 0)
    {
          $this->form_validation->set_message('is_bk_decimal','Bk points decimal value should be incremented by 0.5');
          return false;
    }

 }
 return true;

Answer 1

You can validate it with one single regex ^\\d+(?:\\.[05]0*)?$ :

if(preg_match('#^\d+(?:\.[05]0*)?$#', $bkpoints)){
    echo 'valid';
}

Explanation:

• ^ : begin of line
• \\d+ : match a digit one or more times
• (?: : start of non-capturing group
  • \\. : match a dot
  • [05] : match 0 or 5
  • 0 : match 0 zero or more times
• ) : End of non-capturing group
• ? : make the group optional
• $ : end of line

online regex demo

Answer 2

Try the is_numeric() function in PHP: http://php.net/manual/en/function.is-numeric.php

It'd return true if the number is an valid number, and return false if it isn't.

Answer 3

Or you could also use the ereg() function:

if(ereg("^([0-9]+|[0-9]{1,3}(,[0-9]{3})*)(.[0-9]{1,2})?$", "0.9")){
  echo "number";
}else{
  echo "not a number";
}