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Questions - kotlin-null-safety

Decouple multiple variable let in Kotlin

I have a separate function that applies different gradient based on specified id, this function returns a compose Brush. When I call this function in my boxscore I have to wrap with let since it retur...
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theblankishappy

android

kotlin

android-jetpack-compose

nullable

kotlin-null-safety

Votes: 0

Answers: 1

Latest Answer

I don't use Compose, so I'm not positive about this, but I would think you can move the contents of the second let block inside the first. When I have a let block with more than one line, I prefer to ...
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Tenfour04

Type mismatch: inferred type is kotlin.collections.ArrayList<LiveData<List<a>>> but Collection<LiveData<List<TypeVariable(Source)>?>> was expected

I tried to use flattenLiveData() but it is exspecting kotlin.collections.ArrayList<LiveData<List<TabDefinition>>> but I am passing in Collection<LiveData<List<TypeVariable(S...
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Muraino

android

kotlin

kotlin-coroutines

android-livedata

kotlin-null-safety

Votes: 0

Answers: 1

Latest Answer

You get this error because of generic types mismatch. Your original generic type List<TabDefinition> is not nullable: val array: kotlin.collections.ArrayList<LiveData<List<TabDefinition...
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Sergio

NavHostFragment initialization results in NullPointerException

I am attempting to set a navHostFragment in my MainActivity.kt file, but the code below results in the error: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.lunchtray/c...
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John Harrington

android

kotlin

android-architecture-navigation

android-navigation

kotlin-null-safety

Votes: 0

Answers: 1

Latest Answer

You forgot to call setContentView(R.layout.activity_main), which means you have no FragmentContainerView and no fragment within it, hence why findFragmentById(R.id.nav_host_fragment) returns null. ...
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ianhanniballake

What is this Kotlin type: (String..String?)

IntelliJ is showing me context hints that my variables are of type (String..String?). I cannot find any mention of it on the internet, what is this type?
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Caleb Bolton

kotlin

types

syntax

nullable

kotlin-null-safety

Votes: 0

Answers: 1

Latest Answer

(String..String?) represents a flexible type with lower bound String and upperbound String? (nullable string). This is not valid Kotlin code (it's not denotable) but it is used in the compiler interna...
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Joffrey

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