如果我使用以下硬代码，请从自定义子菜单页：

$post_id = 111;
$flightCategory = array( 25 );
wp_set_object_terms( $post_id, $flightCategory, \'flight_categories\' );

并刷新页面，它只需将所需的自定义分类术语分配给CPT。但是如果我继续下面的代码，我将从<form>, 它不像以前那样工作。

if( $flightID !== NULL && $flightCat !== \'-1\' && !empty( $flightCat ) ) {
    $flightCount = count( $flightID );
    foreach ( $flightID as $post_id ) {
        $flightCategory = array( $flightCat ); //inactive = 25, active = 26
        wp_set_object_terms( $post_id, $flightCategory, \'flight_categories\' );
    }
    $success = sprintf( __(\'<strong>SUCCESS:</strong> %d Flight information has been affected\', \'textdomain\'), $flightCount);
} else {
    $error = __(\'<strong>ERROR:</strong> You can\\\'t pass any empty field\', \'textdomain\');
}

这个代码块的作用是，它简单地添加了名为“25”的新术语和slug“25”。我尝试不传递如下数组：

$flightCategory = $flightCat;

但结果是一样的。我做错了什么？

$flightCategory = array( 25 );
var_dump( $flightCategory );
wp_set_object_terms( $post_id, $flightCategory, \'flight_categories\' );

$flightCategory = array( \'25\' );
var_dump( $flightCategory );
wp_set_object_terms( $post_id, $flightCategory, \'flight_categories\' );

array(1) { [0]=> int(25) }

array(1) { [0]=> string(2) "25" }