Re: PHP Newbie can't evaluate numerical string as number

Path	csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!newsreader4.netcologne.de!news.netcologne.de!newsfeed.arcor.de!newsspool4.arcor-online.net!news.arcor.de.POSTED!not-for-mail
Content-Type	text/plain; charset="UTF-8"
Message-ID	<5823112.UsPfZmn7uG@PointedEars.de> (permalink)
From	Thomas 'PointedEars' Lahn <PointedEars@web.de>
Reply-To	Thomas 'PointedEars' Lahn <php@PointedEars.de>
Organization	PointedEars Software (PES)
Date	Mon, 07 Nov 2011 23:49:05 +0100
User-Agent	KNode/4.4.11
Content-Transfer-Encoding	8Bit
Subject	Re: PHP Newbie can't evaluate numerical string as number
Newsgroups	comp.lang.php
References	<A8OdnXgegKYUmyXTnZ2dnUVZ7ridnZ2d@bt.com>
Followup-To	comp.lang.php
MIME-Version	1.0
Lines	24
NNTP-Posting-Date	07 Nov 2011 23:49:06 CET
NNTP-Posting-Host	2b58250d.newsspool4.arcor-online.net
X-Trace	DXC=b5U7eeh`>o]\9P[:DUn00Q4IUK<Cl32<Q4Fo<]lROoRQ8kF<OcfhCO[N7R:9EjSaT_DZm8W4\YJN\;?f@h5gMfb\3koVXd8EHBT1JDSFVk]e3[
X-Complaints-To	usenet-abuse@arcor.de
Xref	x330-a1.tempe.blueboxinc.net comp.lang.php:3710

Followups directed to: comp.lang.php

Show key headers only | View raw

Graham wrote:

> I'm a Perl veteran (well almost!) but a PHP newbie. […]
> <?php
> $formula = "!big_number - !small_number";
> ?>
> […]
> $big_number = 30000;
> $small_number = 3000;
> $formula = str_replace("!", "$", $formula);
> eval("\$formula = \"$formula\";");

You don't want a string, so don't make a string – remove the `\"'.
(I don't think Perl is so much different in that regard.)

> […]
> The above gives me...'formula = 30000 - 3000'
> when of course what I want is...'formula = 27000'

HTH

PointedEars
-- 
When all you know is jQuery, every problem looks $olvable.

Thread

PHP Newbie can't evaluate numerical string as number "Graham" <graham.stow@stowassocs.co.uk> - 2011-11-07 16:25 +0000
  Re: PHP Newbie can't evaluate numerical string as number The Natural Philosopher <tnp@invalid.invalid> - 2011-11-07 16:56 +0000
  Re: PHP Newbie can't evaluate numerical string as number Denis McMahon <denismfmcmahon@gmail.com> - 2011-11-07 17:52 +0000
    Re: PHP Newbie can't evaluate numerical string as number "Graham" <graham.stow@stowassocs.co.uk> - 2011-11-08 08:41 +0000
      Re: PHP Newbie can't evaluate numerical string as number Erwin Moller <Since_humans_read_this_I_am_spammed_too_much@spamyourself.com> - 2011-11-08 09:56 +0100
        Re: PHP Newbie can't evaluate numerical string as number "Graham" <graham.stow@stowassocs.co.uk> - 2011-11-08 09:35 +0000
          Re: PHP Newbie can't evaluate numerical string as number Denis McMahon <denismfmcmahon@gmail.com> - 2011-11-08 09:57 +0000
            Re: PHP Newbie can't evaluate numerical string as number Tim Streater <timstreater@greenbee.net> - 2011-11-08 10:08 +0000
              Re: PHP Newbie can't evaluate numerical string as number Denis McMahon <denismfmcmahon@gmail.com> - 2011-11-08 17:49 +0000
            Re: PHP Newbie can't evaluate numerical string as number "Graham" <graham.stow@stowassocs.co.uk> - 2011-11-08 10:27 +0000
  Re: PHP Newbie can't evaluate numerical string as number Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-11-07 23:49 +0100
  Re: PHP Newbie can't evaluate numerical string as number Jonathan Stein <jstein@image.dk> - 2011-11-08 11:19 +0100

csiph-web