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Mathmatical Operators
Posted: Thu Oct 21, 2004 5:22 am
by dubs
Code: Select all
<?php
$cart[$Product][0] = $cart[$Product][0] - $Qty;
?>
The above removes the value of $Qty from Qty index in my array. At the moment the operator is hardcoded but would prefer to pass in the operator via a url
I've tried this but get an error
$cart[$Product][0] = $cart[$Product][0] $Operator $Qty;
or
$cart[$Product][0] $Operator = $Qty;
Both give me errors, is there way of doing this in php

Posted: Thu Oct 21, 2004 6:14 am
by Tubbietoeter
Write yourself a function for this and evaluate $Operator within the function.
Posted: Thu Oct 21, 2004 5:42 pm
by rehfeld
tip:
instead of writting
you can do this type of stuff
Code: Select all
<?php
$foo -= $bar;
$foo += $bar;
$foo %= $bar;
$foo /= $bar;
?>
etc....
the only way to pass in the operator as a variable would be to use eval(), which is a bad bad thing to use usually. its slow, and has security issues. Much better would be to do this type of stuff:
Code: Select all
<?php
if ($operator === '+') {
$foo += $bar;
} elseif ($operator === '-') {
$foo -= $bar;
} // etc....
?>
but in the end, using a class, or at least a set of functions, will be the best answer.
if you want a nice little shopping cart class i have one. Youll need to learn how to use classes.
Posted: Fri Oct 22, 2004 3:42 am
by dubs
Cheer worked a treat
Posted: Sun Oct 24, 2004 7:27 pm
by mudkicker
you can change that if/elseif loop with a switch() loop, too.