kotlin-stdlib/kotlin.collections/eachCount

eachCount

expect fun <T, K> Grouping<T, K>.eachCount(): Map<K, Int>

actual fun <T, K> Grouping<T, K>.eachCount(): Map<K, Int>

Groups elements from the Grouping source by key and counts elements in each group.

Return

a Map associating the key of each group with the count of elements in the group.

Since Kotlin

1.1

Samples

import samples.*
fun main() { 
   //sampleStart 
   val words = "one two three four five six seven eight nine ten".split(' ')
val frequenciesByFirstChar = words.groupingBy { it.first() }.eachCount()
println("Counting first letters:")
assertPrints(frequenciesByFirstChar, "{o=1, t=3, f=2, s=2, e=1, n=1}")

val moreWords = "eleven twelve".split(' ')
val moreFrequencies = moreWords.groupingBy { it.first() }.eachCountTo(frequenciesByFirstChar.toMutableMap())
assertPrints(moreFrequencies, "{o=1, t=4, f=2, s=2, e=2, n=1}") 
   //sampleEnd
}

actual fun <T, K> Grouping<T, K>.eachCount(): Map<K, Int>

Groups elements from the Grouping source by key and counts elements in each group.

Return

a Map associating the key of each group with the count of element in the group.

Since Kotlin

1.1

actual fun <T, K> Grouping<T, K>.eachCount(): Map<K, Int>

Groups elements from the Grouping source by key and counts elements in each group.

Return

a Map associating the key of each group with the count of elements in the group.

Since Kotlin

1.1

Samples

import samples.*
fun main() { 
   //sampleStart 
   val words = "one two three four five six seven eight nine ten".split(' ')
val frequenciesByFirstChar = words.groupingBy { it.first() }.eachCount()
println("Counting first letters:")
assertPrints(frequenciesByFirstChar, "{o=1, t=3, f=2, s=2, e=1, n=1}")

val moreWords = "eleven twelve".split(' ')
val moreFrequencies = moreWords.groupingBy { it.first() }.eachCountTo(frequenciesByFirstChar.toMutableMap())
assertPrints(moreFrequencies, "{o=1, t=4, f=2, s=2, e=2, n=1}") 
   //sampleEnd
}