is_user_member_of_blog( int $user_id = 0, int $blog_id = 0 ): bool

1145function is_user_member_of_blog( $user_id = 0, $blog_id = 0 ) {1146	global $wpdb;1147 1148	$user_id = (int) $user_id;1149	$blog_id = (int) $blog_id;1150 1151	if ( empty( $user_id ) ) {1152		$user_id = get_current_user_id();1153	}1154 1155	/*1156	 * Technically not needed, but does save calls to get_site() and get_user_meta()1157	 * in the event that the function is called when a user isn't logged in.1158	 */1159	if ( empty( $user_id ) ) {1160		return false;1161	} else {1162		$user = get_userdata( $user_id );1163		if ( ! $user instanceof WP_User ) {1164			return false;1165		}1166	}1167 1168	if ( ! is_multisite() ) {1169		return true;1170	}1171 1172	if ( empty( $blog_id ) ) {1173		$blog_id = get_current_blog_id();1174	}1175 1176	$blog = get_site( $blog_id );1177 1178	if ( ! $blog || ! isset( $blog->domain ) || $blog->archived || $blog->spam || $blog->deleted ) {1179		return false;1180	}1181 1182	$keys = get_user_meta( $user_id );1183	if ( empty( $keys ) ) {1184		return false;1185	}1186 1187	// No underscore before capabilities in $base_capabilities_key.1188	$base_capabilities_key = $wpdb->base_prefix . 'capabilities';1189	$site_capabilities_key = $wpdb->base_prefix . $blog_id . '_capabilities';1190 1191	if ( isset( $keys[ $base_capabilities_key ] ) && 1 === $blog_id ) {1192		return true;1193	}1194 1195	if ( isset( $keys[ $site_capabilities_key ] ) ) {1196		return true;1197	}1198 1199	return false;1200}