Factoring

[mberman]

I'm trying to make a script to find factors of numbers... The numbers that evenly divide into a given number. I've got part of a script, an example of which can be seen here:

http://www.uni.uiuc.edu/~mberman1/ethan/factor/?mode=doFactor&number=9

(it'll use the number 9).

My code is below, and my problem is this. When you view the example, it'll display all of the possible divisions - both the integers and the decimal numbers. I only want the integer numbers (1,2,3, etc.) displayed. I do NOT want the decimal numbers (1.12321412424, 1123.124214124124, etc.) displayed.

Is there some function to do this, or can anyone think of a way to only display the integer numbers?

TIA

<?PHP
$mode = $_GET['mode'];
        if($mode == "") {
                include("form.htm");
        } elseif ($mode = "doFactor") {
                $number = $_GET['number'];
                for ($i = 1; $i <= $number; $i++) {
                        $tnum = $number/$i;
                        echo $i . ":" . $tnum;
                        echo "<br>";
                }
        }

?>

[Gary_King]

$mode = $_GET['mode'];

if ($mode == "")
{
	//include ("form.htm");
}
elseif ($mode="doFactor")
{
	$number=$_GET['number'];

for ($i=1; $i <= $number; $i++)
{
	$tnum = $number / $i;

	if (is_int($i) and is_int($tnum))
	{
		echo $i . ":" . $tnum;
		echo "<br />";
	}
}
}

[mberman]

Ah hah. Thanks! How do people find out about these functions? Is it just experience, or is there a search on PHP.net I don't know about?

[Weedpacket]

Originally posted by mberman
or is there a search on PHP.net I don't know about?

Yes, it's called the "table of contents" and can be found in the manual. 🙂

[Gary_King]

Yep; it's not like they try to hide the functions from you on purpose and make an easter egg hunt for you to find the functions yourself :p This isn't Microsoft / ASP here 😃