In the Advanced Settings, there's an option called "Scanning always available - Let Google's location service and other apps scan for networks, even when Wi-Fi is off".
As far as I know, the feature came disabled by default, and Android asked you the first time you turned off Wi-Fi if you wanted it on, so it's not really the same as iOS. On the other hand, some people have complained that upgrading to Android 6 has turned it on for them, but that might have been a bug.
In any case, this is a passive scan, it didn't connect you again after you moved places or during the night.
As far as I know, the feature came disabled by default, and Android asked you the first time you turned off Wi-Fi if you wanted it on, so it's not really the same as iOS. On the other hand, some people have complained that upgrading to Android 6 has turned it on for them, but that might have been a bug.
In any case, this is a passive scan, it didn't connect you again after you moved places or during the night.