Detecting Percents

[Neko_D]

So I am trying to use regular expressions to detect if someone put a percent value in my discount field. However I am not sure how exactly to make it detect any kind of percent. I want it to be able to calculate percents with any kind of imaginable percent. Like 45% or 45.67% or .45% or 0.000005%. Here is the regular expression I am using currently.

eregi("[0-9]*[:punct:]?[0-9]*%

It does not pick up what I want it too any suggestions?

[Piranha]

I don't know if this is a stupid suggestion or not, it will work but might not be the best way:

$all = "45.5%";
$percent = last char of $all;
$number = all but last char of $all;
if ($percent == "%" && is_numeric($number)
   echo "success";
else
   echo "failure";

[Neko_D]

Piranha wrote:

I don't know if this is a stupid suggestion or not, it will work but might not be the best way:

$all = "45.5%";
$percent = last char of $all;
$number = all but last char of $all;
if ($percent == "%" && is_numeric($number)
   echo "success";
else
   echo "failure";

That is definitely a quick fix way. I am just not 100% comfortable with the string disecting functions that is all.

[laserlight]

In this case, you mainly need [man]substr/man for Piranha's suggestion.

[NogDog]

$discount = trim($discount);
if(substr($discount, -1) == '%') // it's a percent
{
   $discountNumber = trim(substr($discount, 0, -1));
   if(is_numeric($discountNumber))
   {
      // we now know that $discountNumber is a valid percentage number
   }
   else
   {
      // a percentage was indicated, but a non-numeric value was entered
   }
}
else
{
   // value entered was not indicated as being a percentage
}