component2所在位置是kotlin.collections.component2,其相关用法介绍如下。

用法一

operator fun <T> Array<out T>.component2(): T
operator fun ByteArray.component2(): Byte
operator fun ShortArray.component2(): Short
operator fun IntArray.component2(): Int
operator fun LongArray.component2(): Long
operator fun FloatArray.component2(): Float
operator fun DoubleArray.component2(): Double
operator fun BooleanArray.component2(): Boolean
operator fun CharArray.component2(): Char
@ExperimentalUnsignedTypes operator fun UIntArray.component2(): UInt
@ExperimentalUnsignedTypes operator fun ULongArray.component2(): ULong
@ExperimentalUnsignedTypes operator fun UByteArray.component2(): UByte
@ExperimentalUnsignedTypes operator fun UShortArray.component2(): UShort

从数组中返回第二个 element

如果此数组的大小小于 2,则抛出 IndexOutOfBoundsException,除非在 Kotlin/JS 中未指定行为。

用法二

operator fun <T> List<T>.component2(): T

从列表中返回第二个 element

如果此列表的大小小于 2,则抛出 IndexOutOfBoundsException

用法三

operator fun <K, V> Entry<K, V>.component2(): V

返回映射条目的值组件。

此方法允许在使用Map时使用解构声明,例如:

for ((key, value) in map) {
    // do something with the key and the value
}