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sumBy

Platform and version requirements: JVM (1.0), JS (1.0), Native (1.0)
inline fun <T> Sequence<T>.sumBy(selector: (T) -> Int): Int

Returns the sum of all values produced by selector function applied to each element in the sequence.

The operation is terminal.

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Licensed under the Apache License, Version 2.0.
https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/sum-by.html