Flow basics in Android Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Flow in Kotlin?

A Flow is a type that can emit multiple values sequentially, asynchronously. It is like a stream of data that you can collect over time.

beginner

How do you collect values from a Flow?

You use the collect terminal operator inside a coroutine to receive emitted values from the Flow.

intermediate

What is the difference between Flow and suspend functions?

suspend functions return a single value asynchronously, while Flow can emit multiple values over time.

beginner

What does the flow { } builder do?

It creates a Flow by defining a block where you can emit values using emit().

beginner

Why should you collect a Flow inside a coroutine?

Because Flow is asynchronous and suspending, collecting it requires a coroutine context to handle the asynchronous stream properly.

Which Kotlin type represents a stream of multiple asynchronous values?

A Flow

B suspend function

C List

D Deferred

Flow is designed to emit multiple values asynchronously over time.

How do you receive values emitted by a Flow?

A Using collect inside a coroutine

B Calling the Flow directly

C Using a for loop

D Using suspend functions only

You must call collect inside a coroutine to receive Flow emissions.

What keyword is used to create a Flow builder?

A emit

B async

C flow

D launch

The flow builder is created with the keyword flow { }.

Which operator is used inside a flow builder to send values?

A return

B send

C collect

D emit

emit() is used inside flow { } to emit values.

What is the main difference between a suspend function and a Flow?

A Suspend functions are faster than Flow

B Suspend functions return one value; Flow emits many

C Suspend functions are synchronous; Flow is asynchronous

D Flow cannot be collected

Suspend functions return a single asynchronous value, while Flow can emit multiple values over time.

Explain what a Flow is and how it differs from a suspend function in Kotlin.

Think about streams of data versus single results.

Describe how to create and collect values from a Flow in Kotlin.

Focus on the flow builder and collection process.