我想循环执行参数

Question

    if(get_post_meta(get_the_ID(),$field,true) && $field == 'is_this_a_job' )
      {

    $today = date('Ymd');   
      $args = array(
  'meta_query' => array(
    array(
     'meta_key'          => 'last_date',
     'orderby'           => 'meta_value_num',
    )
  )
);