(WordPress) table_rows_count()

/**
 * Count table rows (<tr>) in the original post content.
 *
 * To count all table rows:
 *   1) If in the loop:          echo table_rows_count()
 *   2) If not, specify post ID: echo table_rows_count( 123 )
 *
 * To count table rows which contains a specific string:
 *   1) If in the loop:          echo table_rows_count( null, 'the string' )
 *   2) If not, specify post ID: echo table_rows_count( 123, 'the string' )
 *
 * In single.php or any singular post template files, you may need to call
 * wp_reset_query() like so:
 *   wp_reset_query();
 *   echo table_rows_count();
 *
 * This function would work well so long as your tables use valid HTML code.
 * E.g. Escape > to &lt; when used in an attribute (e.g. data-foo="Bar &lt;"),
 * and always close a <tr> with a </tr>.
 */
// YOU CAN COPY JUST THE FUNCTION BELOW WITHOUT THE ABOVE COMMENTS SECTION...
function table_rows_count( $post = null, $string = '' ) {
    $post_content = get_post_field( 'post_content', $post );
    $rows = preg_split( '#<tr\b(.*?)>#', $post_content );
    $rows_count = 0;

    $count_only = ( strlen( trim( $string ) ) < 1 );
    foreach ( (array) $rows as $row ) {
        if ( false === stripos( $row, '</tr>' ) ) {
            continue;
        }

        if ( $count_only ) {
            $rows_count++;
            continue;
        }

        if ( false !== stripos( $row, $string ) ) {
            $rows_count++;
        }
    }

    return $rows_count;
}