Question

Here is my code to list all category as a list item:

if ($xml) {
    foreach($xml->children() as $IRXML) {                                                                           // SHOW ONLY 5 NEWS ITEMS

        foreach($IRXML->children() as $newsrelease) {                                               // EACH NEWSRELEASE IS ONE SUBCHILD

            // echo "   <div class='news-image'>";
            // echo "<img src='/wp-content/themes/bby/images/news-story-01.jpg' alt=''>";
            // echo "</div>";

            $categories = $newsrelease->Categories;
            foreach($categories->children() as $category) {
                if ($category != "NA") {
                    echo "<li class='category ".$category."'>".$category."</li> ";
                }
            }

        }
    }

}

What I wanted to do is only to display a category without duplicating it.

Answer 1

$list_cache = array();

if ($xml)
{
    foreach($xml->children() as $IRXML) 

    foreach($IRXML->children() as $newsrelease) 
    {

        $categories = $newsrelease->Categories;

        foreach($categories->children() as $category)
        {
            if ($category != "NA")
            {
                $print_category = "<li class='category ".$category."'>".$category."</li> ";

                if( !in_array($print_category, $list_cache) )    //check if you've stored in previously in this array. In such case, in_array will return true. 
                {
                    $list_cache[] = $print_category;
                    echo $print_category;
                }
            }
        }
    }
}

Check out the in_array function from the documentation.