Question

for some reason $post is always < 0. The indoxOf function works great. I use it on ohter codes and it works great

for some reason even after I add the element like this array_push($groups, $tempDon); on the next loop i continues to return -1

$donations = $this->getInstitutionDonations($post->ID);

            $groups=array();

            foreach( $donations as $don ) : setup_postdata($don); 

                $pos = $this->indexOf($don, $groups);

                print_r($pos);

                if($pos < 0)
                {
                    $tempDom = $don;

                    $tempDon->count = 1;

                    array_push($groups, $tempDon);
                }
                else
                {
                    $tempDom = $groups[$pos];

                    $tempDon->count++;

                    array_splice($tempDon);

                    array_push($groups, $tempDon);

                    echo '<br><br><br>ahhhhhhhhhh<br><br>';
                }
            endforeach;

     protected function indexOf($needle, $haystack) {            // conversion of JavaScripts most awesome
        for ($i=0;$i<count($haystack);$i++) {         // indexOf function.  Searches an array for
                if ($haystack[$i] == $needle) {       // a value and returns the index of the *first*
                        return $i;                    // occurance
                }
        }
        return -1;
    }

Answer 1

This looks like an issue of poor proofreading to me (note $tempDom vs $tempDon):

                $tempDom = $don;

                $tempDon->count = 1;

                array_push($groups, $tempDon);

Your else block has similar issues.

I also completely agree with @hakre’s comment regarding syntax inconsistencies.

EDIT

I’d also like to recommend that you make use of PHP’s built-in array_search function in the body of your indexOf method rather than rolling your own.