Flow exception handling in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to catch exceptions in a Flow using the catch operator.

Kotlin

flowOf(1, 2, 3)
    .[1] { e -> emit(-1) }

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Acatch

Bcollect

Cmap

Dfilter

Attempts:

3 left

💡 Hint

Common Mistakes

Using collect instead of catch to handle exceptions.

Using map or filter which do not handle exceptions.

The catch operator is used to handle exceptions in a Flow.

2fill in blank

medium

Complete the code to emit a fallback value when an exception occurs in the Flow.

Kotlin

flow {
    emit(1)
    throw RuntimeException("Error")
}.catch { [1] -> emit(0) }

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Ae

Bexception

Cerror

Dex

Attempts:

3 left

💡 Hint

Common Mistakes

Using a parameter name that is not used in the lambda.

Forgetting to name the exception parameter.

The lambda parameter in catch is commonly named e to represent the exception.

3fill in blank

hard

Fix the error in the code to properly handle exceptions in the Flow.

Kotlin

flow {
    emit(1)
    throw Exception("Fail")
}.[1] { e -> emit(-1) }

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AcatchError

BhandleException

ConError

Dcatch

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent operators like catchError or onError.

Trying to handle exceptions outside the Flow operators.

The correct operator to handle exceptions in a Flow is catch.

4fill in blank

hard

Fill both blanks to emit values and handle exceptions with catch.

Kotlin

flow {
    emit(10)
    emit(20)
    throw Exception("Oops")
}.[1] { e ->
    emit([2])
}

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Acatch

Bcollect

C30

D-1

Attempts:

3 left

💡 Hint

Common Mistakes

Using collect instead of catch for exception handling.

Emitting a value that does not indicate an error fallback.

Use catch to handle exceptions and emit a fallback value like -1.

5fill in blank

hard

Fill all three blanks to create a Flow that emits numbers, handles exceptions, and collects the results.

Kotlin

val flow = flow {
    emit(1)
    emit(2)
    throw Exception("Error")
}

flow.[1] { e ->
    emit([2])
}.[3] { value ->
    println(value)
}

Drag options to blanks, or click blank then click option'

Acatch

B0

Ccollect

Dmap

Attempts:

3 left

💡 Hint

Common Mistakes

Using map instead of catch for exception handling.

Forgetting to collect the Flow to trigger execution.

Emitting a wrong fallback value.

Use catch to handle exceptions, emit a fallback value 0, and then collect to process the emitted values.