Question

I have the following code

//check out the tags, if it allready exist update with 1 if not create new record
        $tag_item = "";
        $tags = explode(" ", $tags);
        foreach($tags as $tag):
            if(!empty($tag) && $tag != " "):
                $t_sql = mysqli_query($link, "SELECT id, times FROM shop_tags WHERE tag='".$tag."'");
                if(mysqli_num_rows($t_sql) == 0):
                    mysqli_query($link, "INSERT INTO shop_tags (tag, times) VALUES ('".$tag."', 1)");
                    //find last updated id of the tags
                    $lastid = mysqli_insert_id($link);
                    $tag_item .= $lastid." ";
                endif;
            endif;
        endforeach;

So I use explode to seperate each tag, but what if a user by accident added to spaces? should I use preg_match first to filter for this? and how do I remove the last white space if there is any?

Answer 1

To remove white spaces, the first though is to use trim(), which you could either do in the loop for each tag

foreach($tags as $tag):
    $tag = trim($tag);

or before:

$tags = explode(" ", $tags);
$tags = array_map('trim', $tags);

In both cases, you will end up having to filter out the empty items in $tags

foreach($tags as $tag):
    $tag = trim($tag); //This line is only required if you didn't use array_map
    if ( empty($tag){
        continue;
    }

So it would possibly just be better to use preg_replace

$tags = preg_replace('/\s\s+/',' ', $tags);
$tags = explode(' ', $tags);

Which would ensure that multiple white spaces are converted into a single space before exploding.