Serves as a utility function to determine whether a key is valid.

$key int|string Required

Cache key to check for validity.

bool Whether the key is valid.

File: wp-includes/class-wp-object-cache.php. View all references

protected function is_valid_key( $key ) {
	if ( is_int( $key ) ) {
		return true;
	}

	if ( is_string( $key ) && trim( $key ) !== '' ) {
		return true;
	}

	$type = gettype( $key );

	if ( ! function_exists( '__' ) ) {
		wp_load_translations_early();
	}

	$message = is_string( $key )
		? __( 'Cache key must not be an empty string.' )
		/* translators: %s: The type of the given cache key. */
		: sprintf( __( 'Cache key must be integer or non-empty string, %s given.' ), $type );

	_doing_it_wrong(
		sprintf( '%s::%s', __CLASS__, debug_backtrace( DEBUG_BACKTRACE_IGNORE_ARGS, 2 )[1]['function'] ),
		$message,
		'6.1.0'
	);

	return false;
}