本文方法及代码示例筛选整理自kotlinlang.org——Kotlin 2.1.20 Released
all 所在包 kotlin.collections.all，其相关用法介绍如下：
用法一
inline fun <T> Array<out T>.all(
predicate: (T) -> Boolean
): Boolean
inline fun ByteArray.all(
predicate: (Byte) -> Boolean
): Boolean
inline fun ShortArray.all(
predicate: (Short) -> Boolean
): Boolean
inline fun IntArray.all(predicate: (Int) -> Boolean): Boolean
inline fun LongArray.all(
predicate: (Long) -> Boolean
): Boolean
inline fun FloatArray.all(
predicate: (Float) -> Boolean
): Boolean
inline fun DoubleArray.all(
predicate: (Double) -> Boolean
): Boolean
inline fun BooleanArray.all(
predicate: (Boolean) -> Boolean
): Boolean
inline fun CharArray.all(
predicate: (Char) -> Boolean
): Boolean
inline fun <T> Iterable<T>.all(
predicate: (T) -> Boolean
): Boolean
@ExperimentalUnsignedTypes inline fun UIntArray.all(
predicate: (UInt) -> Boolean
): Boolean
@ExperimentalUnsignedTypes inline fun ULongArray.all(
predicate: (ULong) -> Boolean
): Boolean
@ExperimentalUnsignedTypes inline fun UByteArray.all(
predicate: (UByte) -> Boolean
): Boolean
@ExperimentalUnsignedTypes inline fun UShortArray.all(
predicate: (UShort) -> Boolean
): Boolean
- 如果所有元素都与给定的 predicate 匹配，则返回
true。
用法二
inline fun <K, V> Map<out K, V>.all(
predicate: (Entry<K, V>) -> Boolean
): Boolean
- 如果所有条目都与给定的 predicate 匹配，则返回
true。
代码示例：
import kotlin.test.*
fun main(args: Array<String>) {
//sampleStart
val isEven: (Int) -> Boolean = { it % 2 == 0 }
val zeroToTen = 0..10
println("zeroToTen.all { isEven(it) } is ${zeroToTen.all { isEven(it) }}") // false
println("zeroToTen.all(isEven) is ${zeroToTen.all(isEven)}") // false
val evens = zeroToTen.map { it * 2 }
println("evens.all { isEven(it) } is ${evens.all { isEven(it) }}") // true
val emptyList = emptyList<Int>()
println("emptyList.all { false } is ${emptyList.all { false }}") // true
//sampleEnd
}
// 输出
zeroToTen.all { isEven(it) } is false
zeroToTen.all(isEven) is false
evens.all { isEven(it) } is true
emptyList.all { false } is true
