variable $radminsuper back to front

Involved Joined: Apr 06, 2008 Posts: 484

Version: 2.3.01

File: links.editadmins.php

Issue:

Code:




if (1==$radminsuper) {   adminmenu($admin_file . '.php?op=mod_authors', _EDITADMINS, 'authors.gif');

registered · Posted: Fri Feb 20, 2009 12:01 am

Could you explain the error you are reporting

Posted: Fri Feb 20, 2009 12:17 am

sorry forgot to write a descriptuion Sad

just wondering if this was back to front or not.....

Code:




1==$radminsuper

Posted: Fri Feb 20, 2009 12:25 am

Readability, it makes more sense the other. But logically it is correct
You can do equality comparisons from variable-number and number-variable. It doesn't change the actual result

Site Admin/Owner Joined: Aug 27, 2002 Posts: 17088

Oh it's much more important than readability. It is the preferred/only way to keep from making the common mistake of a variable assignment when you actually meant to do a variable comparison Smile

. Note that the same is true when using the === operator.

$radminsuper = 1 which assigns $radminsuper the value of 1 when what you really meant was to a comparison $radminsuper == 1 Wink

Example: You want to compare the value of variable $radminsuper to see if it equals 1.

Typed correctly it should read (note the double == sign used for comparison)
if ($radminsuper == 1) /* rest of code */

However, if you mistakenly type (note the single = sign used for assignment in PHP but used for comparison in most any other language) the IF clause will always be TRUE and PHP will let you happily/blissfully carry on and can leave you scratching your head (or whatever killing me

) trying to figure out what's going on when no errors are thrown but the results are wrong! Note that PHP v5.? will throw a Warning that you may be using the wrong operator but it's still the best way to be all versions protected from your own devices!
if ($radminsuper = 1) /* rest of code */

So to avoid the potential and common error of assignment instead of comparison you reverse it
if (1==$radminsuper) /* rest of code */

That way, even if you make the same mistake it will not accept it and PHP will throw an ERROR.
if (1=$radminsuper) /* rest of code */

Posted: Fri Feb 20, 2009 3:08 am

mmmm I see, you have spiked my interest and just cost me the next day or so mucking around Sad

Posted: Fri Feb 20, 2009 3:21 am

Just trying to keep you interested Wink

Posted: Fri Feb 20, 2009 6:53 pm

That is an interesting thought Raven. It is a good trick.

Posted: Fri Feb 20, 2009 7:28 pm

yep... will save me some time now Very Happy