How to Convert WordPress Tags to Hashtags

function convert_tags_to_hashtags() {
    // Get the current tags for the post
    $tags = get_the_tags();

    // Check if there are any tags
    if ($tags) {
        // Initialize an empty string for the new hashtagged tags
        $new_tags = '';

        // Iterate through the tags and prepend hashtags
        foreach ($tags as $tag) {
            $new_tags .= '#' . $tag->name . ' ';
        }

        // Return the new hashtagged tags
        return $new_tags;
    }

    // If no tags, return an empty string
    return '';
}

You can then use the `convert_tags_to_hashtags()` function in your WordPress theme files to display tags as hashtags as desired. For instance, you might insert this function within `single.php` or `content.php` to show tags as hashtags within a post.

Alternative:

function wptag_to_hashtag($mywp_post)
{
    $content = $mywp_post->post_content;
    $ID = $mywp_post->ID;
    preg_match_all('/B(#[a-zA-Z]+b)/', $content, $matches, PREG_PATTERN_ORDER);
    if (isset($matches[1])) {
        foreach ($matches[1] as $matchKey) {
            wp_set_post_tags($ID, $matchKey, true);
        }
    }
}
add_action('post_save', 'wptag_to_hashtag', 10, 2);
function hashtagger($content)
{
    $siteurl = get_site_url(); // get wordpress siteurl to create url for tags
    $content = preg_replace('/([^a-zA-Z-_&])#([a-zA-Z_]+)/', "$1#$2", $content);
    return $content;
}
add_filter('the_content', 'hashtagger');

Add this snippet to the functions.php file of your active theme.