在每个输出之后显示逗号，而不是在最后一个输出之后 - Display commas after every output not after last

Display commas after every output not after last

我有这个函数代码:

 public function getMovieCategoryDetails($movieid){
        $movieid = mysql_real_escape_string($movieid);
        $tags = array();
         if ( !( $e = mysql_query("SELECT * FROM movie_tags WHERE id IN (SELECT tag_id FROM movie_tags_join WHERE movie_id=$movieid)") ) ) 
{
            exit( mysql_error( ) );
        }
while ( 0 < mysql_num_rows( $e ) && ( $s = mysql_fetch_array( $e ) ) )
        {
            extract( $s );
            $tags[$id] = array( );
            $tags[$id]['tag'] = $tag;
        }
        return $tags;
    }

，输出代码为:

{foreach from=$tags key=id item=val name=tags}
{$val.tag}
{/foreach}

现在是show: category1 category2 category3

我想要:category1,category2,category3

我首先建议使用smarty变量。

{foreach from=$tags key=id item=val name=tags}
    {if !$smarty.foreach.tags.first},{/if}{$val.tag}
{/foreach}

参考smarty文档