Flow is cold!, means it emits data only when it is collected.
Also Flow cannot hold data, take it as a pipe in which water is flowing , data in flow only flows , not stored(no .value function).
Unlike flow , stateflow and sharedflow are hot streams means they emit data even when there is no collector. Also if there are multiple collectors ,a new flow will be run for each collector, completely independent from each other.
SharedFlow and StateFlow are Flows that allows for sharing itself between multiple collectors, so that only one flow is effectively run for all of the simultaneous collectors. If you define a SharedFlow that accesses databases and it is collected by multiple collectors, the database access will only run once, and the resulting data will be shared to all collectors.
What are the differences between SharedFlow and StateFlow?
StateFlow
Stateflow takes an initial value through constructor and emits it immediately
when someone starts collecting.
Stateflow is identical to LiveData.
LiveData automatically unregisters the consumer when the view goes to the STOPPED
state. When collecting a StateFlow this is not handled automatically , you can
use repeatOnLifeCyCle scope if you want to unregister the consumer on STOPPED
state.
If you want current state use stateflow(.value).
SharedFlow
StateFlow only emits last known value , whereas sharedflow can configure how many
previous values to be emitted.
If you want emitting and collecting repeated values , use sharedflow.
Summary
In summary, use StateFlow when you need to manage and share a single state with multiple collectors, and use SharedFlow when you need to share a stream of events or signals among collectors without holding any state.