【Kotlin/Android】配列(list)から条件にマッチする要素を取得！findとfirstの違い

inline fun <T> Array<out T>.find(
    predicate: (T) -> Boolean
): T?

val numbers = listOf(1, 2, 3, 4, 5, 6, 7)
val firstOdd = numbers.find { it % 2 != 0 }
val lastEven = numbers.findLast { it % 2 == 0 }
val result = numbers.find { it > 10 }

print(firstOdd) // 1
print(lastEven) // 6
print(result)   // null

fun <T> Array<out T>.first(): T

inline fun <T> Array<out T>.first(
    predicate: (T) -> Boolean
): T

val numbers = listOf(1, 2, 3, 4, 5, 6, 7)
val first = numbers.first()
val firstOdd = numbers.first { it % 2 != 0 }
val last = numbers.last()
val lastEven = numbers.last { it % 2 == 0 }
val result = numbers.first { it > 10 }
// java.util.NoSuchElementException: Collection contains no element matching the predicate.

print(first)    // 1
print(firstOdd) // 1
print(last)     // 7
print(lastEven) // 6

val numbers: List<Int> = emptyList()
  
val first = numbers.firstOrNull()
val last = numbers.lastOrNull()

print(first)    // null
print(last)     // null