Quadratic

Path: csiph.com!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: "J.O. Aho" Newsgroups: comp.lang.php Subject: Re: test prog inpu tpost Date: Fri, 1 Jan 2016 09:40:44 +0100 Lines: 80 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Trace: individual.net 1Gtbj4HkpDYd5s0CylHWTg+sggxbieeNNzo8WaTtjXDXWF3+0l Cancel-Lock: sha1:FC3CCf6efeeU0XLmvRTiROpXvB0= X-Enigmail-Draft-Status: N1110 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 In-Reply-To: Xref: csiph.com comp.lang.php:16049 On 01/01/2016 03:22 AM, Lew Pitcher wrote: > On Thursday December 31 2015 20:57, in > comp.lang.php, "vjp2.at@at.BioStrategist.dot.dot.com" > wrote: > >> >> Should this work? > >> I'm stuck with lynx browser for a few days and can't tell > > That shouldn't stop you, assuming that you have a PHP-enabled webserver to > host the page on. > > Lynx, like all browsers, just renders the html sent to it by the server. > > PHP code executes on the server. > > If the html with PHP is served from a PHP-enabled web server, lynx will render > the results correctly. > >> >> >> Quadratic >> >> >> > $t; > > What is $t ? > Why are you trying to execute it as a php statement? I think the OP is trying to initiate the variable before use, so to not get errors with uninitiated variables, but will instead generate the error as they are uninitiated. >> $b=$_POST['b'];$a=$_POST['a'];$c=$_POST['c']; > > Here, you should test whether the page is invoked from a GET or a POST. None > of the $_POST variables will be set on the initial GET, and your later > computation will be invalid. If allowing both, you could use $_REQUEST, but you should avoid to use that, as it makes it easier to do unintended things. Should always validate that you have got what you wanted in a request, so should use for example is_numeric() to verify that the value is not something else and stop the processing already here if it's invalid data. > >> if($t<=0) >> $t=(-1)*$t; >> $x=(-2*$c)/($b+(sqrt($t))); >> $y=(-2*$c)/($b-(sqrt($t))); >> echo sprintf("Solution in Addition = %f in Subtraction = %f" ,$x,$y); > > This last stmt is overly complicated. Why wouldn't you just > printf("Solution in Addition = %f in Subtraction = %f" ,$x,$y); > ? PHP allows you to use a lot of different ways, for example echo "Solution in Addition = {$x} in Subtraction = {$y}"; would work in this case too. >> ?> >>