Kotlin extensions for Android: How to use bundleOf

Question

Documentation says:

fun bundleOf(vararg pairs: Pair<String, Any?>): Bundle

Returns a new Bundle with the given key/value pairs as elements.

I tried:

   val bundle = bundleOf {
       Pair("KEY_PRICE", 50.0)
       Pair("KEY_IS_FROZEN", false)
   }

But it is showing error.

Solution 1

If it takes a vararg, you have to supply your arguments as parameters, not a lambda. Try this:

val bundle = bundleOf(
               Pair("KEY_PRICE", 50.0),
               Pair("KEY_IS_FROZEN", false)
             )

Essentially, change the { and } brackets you have to ( and ) and add a comma between them.

Another approach would be to use Kotlin's to function, which combines its left and right side into a Pair. That makes the code even more succinct:

val bundle = bundleOf(
    "KEY_PRICE" to 50.0,
    "KEY_IS_FROZEN" to false
)

Solution 2

How about this?

val bundle = bundleOf (
   "KEY_PRICE" to 50.0,
   "KEY_IS_FROZEN" to false
)

to is a great way to create Pair objects. The beauty of infix function with awesome readability.

Solution 3

Just to complete the other answers:

First, to use bundleOf, need to add implementation 'androidx.core:core-ktx:1.0.0' to the build.gradle then:

var bundle = bundleOf("KEY_PRICE" to 50.0, "KEY_IS_FROZEN" to false)

Comments

[Etienne Lawlor]

I have added the plugin apply plugin: 'kotlin-android-extensions' , but bundleOf() doesn't resolve itself. Is there something else to set up?

[Chandra Sekhar]

bundleOf has nothing to do with android-kotlin-extension. It is part of core library. Ideally it should be available.

[sbearben]

@toobsco42 bundleOf is part of the Android KTX extension functions. Check out the docs here: developer.android.com/kotlin/ktx (it's in the androidx.core.os package)

[Oleksandr Bodashko]

@toobsco42 change bndleOf import to "androidx.core.os.bundleOf"

[Rishabh Deep Singh]

Does this auto converts or check if the variable is Parcelable or not?