wp_set_post_categories( int $post_ID, array|int $post_categories = array(), bool $append = false )

为文章设置类别。
Set categories for a post.

目录锚点：#说明#参数#源码#笔记

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说明（Description）

如果未设置post categories参数，则使用默认类别。

参数（Parameters）

源码（Source）

/**
 * Set categories for a post.
 *
 * If the post categories parameter is not set, then the default category is
 * going used.
 *
 * @since 2.1.0
 *
 * @param int       $post_ID         Optional. The Post ID. Does not default to the ID
 *                                   of the global $post. Default 0.
 * @param array|int $post_categories Optional. List of categories or ID of category.
 *                                   Default empty array.
 * @param bool      $append         If true, don't delete existing categories, just add on.
 *                                  If false, replace the categories with the new categories.
 * @return array|bool|WP_Error
 */
function wp_set_post_categories( $post_ID = 0, $post_categories = array(), $append = false ) {
	$post_ID = (int) $post_ID;
	$post_type = get_post_type( $post_ID );
	$post_status = get_post_status( $post_ID );
	// If $post_categories isn't already an array, make it one:
	$post_categories = (array) $post_categories;
	if ( empty( $post_categories ) ) {
		if ( 'post' == $post_type && 'auto-draft' != $post_status ) {
			$post_categories = array( get_option('default_category') );
			$append = false;
		} else {
			$post_categories = array();
		}
	} elseif ( 1 == count( $post_categories ) && '' == reset( $post_categories ) ) {
		return true;
	}

	return wp_set_post_terms( $post_ID, $post_categories, 'category', $append );
}

笔记（Notes）

如果要以编程方式将文章从一个类别移动到另一个类别：