[RESOLVED] Using the OR operator in php

juniper747

I am running the following error checking code, whereby someone has to enter in a theme, via a text input in html. However it is not working... I do not think it is iterating through each theme. What am I doing wrong?

if ($theme !==('Animal' || 'Plant' || 'Inorganic' || 'Supernatural' )) {
$errorMsg = ' * You did not select one of the given Themes:<br />';
}

Weedpacket

You need to OR whole comparisons, just just part.

if ($theme !=='Animal' || $theme !=='Plant' || $theme !=='Inorganic' || $theme !=='Supernatural' ) {

But better would be an array that has all these and check them all at once

if(!in_array($theme, array('Animal', 'Plant', 'Inorganic', 'Supernatural')) {

Especially if this list is also used elsewhere in the script; because then you'd only need to write the list once and say

if(!in_array($theme, $given_themes) {

NogDog

Weedpacket;10992250 wrote:
You need to OR whole comparisons, just just part.
if ($theme !=='Animal' || $theme !=='Plant' || $theme !=='Inorganic' || $theme !=='Supernatural' ) {
...

Note that if you use this approach, you probably want to use "&&" instead of "||" for this particular logic. Or else you could negate a series of equivalence tests:

if ( ! ( $theme == 'Animal'    || 
         $theme == 'Plant'     ||
         $theme == 'Inorganic' ||
         $theme == 'Supernatural' ) )
{
    $errorMsg = ' * You did not select one of the given Themes:<br />';
}

But I tend to prefer the array approach when you get to this many things to check.

Weedpacket

NogDog wrote:
Note that if you use this approach, you probably want to use "&&" instead of "||" for this particular logic.

Uh, yeah, you're right (it's not this AND it's not this AND it's not this...). One more reason why using an array would be less trouble.

juniper747

Thanks guys, a lot. I ended up going with the array, works perfectly!