What does the |= operator do in Java?

Question

While reading the Android guide to Notifications, I stumbled across this:

Adding vibration

You can alert the user with th

Answer 1

In this case, notification.defaults is a bit array. By using |=, you're adding Notification.DEFAULT_VIBRATE to the set of default options. Inside Notification, it is likely that the presence of this particular value will be checked for like so:

notification.defaults & Notification.DEFAULT_VIBRATE != 0 // Present