Re: Perfect Squares
| From: | Jason Barnett | Date: | Tue, 25 May 2004 23:59:21 +0000 |
| Subject: | Re: Perfect Squares | ||
| References: | 1 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-186965@lists.php.net to get a copy of this message | ||
Stephen Craton wrote:
I'm in a bit of a pickle. I need to find out if a variable is a perfect square or not, and this needs to test for decimal numbers as well, such as 2.25. The thing is, the only function I've found in PHP is gmp_perfect_square() which isn't supported on my web server, and I don't know how to compile the GMP code into PHP on my windows box. So, how exactly would you go about finding out if something is a perfect square or not?It's been a while since I studied this in math, so I figured I'd find out the definition of perfect square. What I found: http://en.wikipedia.org/wiki/Perfect_square Neither of those definitions fit what for your example number 2.25. For instance, $sqrt = sqrt($number); if ($sqrt * $sqrt == $number) { //should always be true, except negative values and possibly rounding }