获取所有分类id

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/*-----------------------------------------------------------------------------------*/
# Get All Categories IDs
/*-----------------------------------------------------------------------------------*/
function tie_get_all_category_ids(){
	$categories = array();
	$get_cats = get_terms( 'category' );
	if ( ! empty( $get_cats ) && ! is_wp_error( $get_cats ) ){
		foreach ( $get_cats as $cat )
			$categories[] = $cat->term_id;
	}
	return $categories;
}

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