Getting undefined variable.. why?

[Freedom-n-Democrazy]

I'm getting:

PHP Notice:  Undefined variable: carttotal

... for this:

$idtotal = $sizestotal + $sizemtotal + $sizeltotal + $sizexltotal;
$carttotal += $idtotal;

 

Why?

[Freedom-n-Democrazy]

$carttotal = +$idtotal;

 

EDIT: While this stopped the PHP notice, it made my calculation thing stop working.

[trq]

Have you defined $carttotal anywhere before trying to add to it?

[MasterACE14]

Have you defined $carttotal anywhere before trying to add to it?

 

something like this would be fine:

$carttotal = 0; // set default
$idtotal = $sizestotal + $sizemtotal + $sizeltotal + $sizexltotal;
$carttotal += $idtotal;

 

or even...

$carttotal = 0; // set default
$carttotal += ($sizestotal + $sizemtotal + $sizeltotal + $sizexltotal);

[AyKay47]

rule of thumb when trying to increment/decrement a variable, the variable must always be set to a value before it can be incremented or decremented.

[Freedom-n-Democrazy]

Hey guys,

 

Nah I hadn't but someone from codingforums.com helped me out so I've got it all sorted. Thanks.