A DataSnapshot contains data from a Database location.
Any time you read data from the Database, you receive the data as a
DataSnapshot. A DataSnapshot is passed to the event callbacks you attach
with on() or once(). You can extract the contents of the snapshot as a
JavaScript object by calling the val() method. Alternatively, you can
traverse into the snapshot by calling child() to return child snapshots
(which you could then call val() on).
A DataSnapshot is an efficiently generated, immutable copy of the data at
a Database location. It cannot be modified and will never change (to modify
data, you always call the set() method on a Reference directly).
A
DataSnapshotcontains data from a Database location.Any time you read data from the Database, you receive the data as a
DataSnapshot. ADataSnapshotis passed to the event callbacks you attach withon()oronce(). You can extract the contents of the snapshot as a JavaScript object by calling theval()method. Alternatively, you can traverse into the snapshot by callingchild()to return child snapshots (which you could then callval()on).A
DataSnapshotis an efficiently generated, immutable copy of the data at a Database location. It cannot be modified and will never change (to modify data, you always call theset()method on aReferencedirectly).