Kotlin學習筆記(24) Use ranges and in.kt

Kotlin學習筆記(24) Use ranges and in.kt

/**
 * Check if a number lies within a range.
 * Check if a number is out of range.
 * Check if a collection contains an object.
 * See http://kotlinlang.org/docs/reference/ranges.html#ranges
 */

fun main(args: Array<String>) {
    val x = args[0].toInt()
    //Check if a number lies within a range:
    val y = 10
    if (x in 1..y - 1)
        println("OK")

    //Iterate over a range:
    for (a in 1..5)
        print("${a} ")

    //Check if a number is out of range:
    println()
    val array = arrayListOf<String>()
    array.add("aaa")
    array.add("bbb")
    array.add("ccc")

    if (x !in 0..array.size - 1)
        println("Out: array has only ${array.size} elements. x = ${x}")

    //Check if a collection contains an object:
    if ("aaa" in array) // collection.contains(obj) is called
        println("Yes: array contains aaa")

    if ("ddd" in array) // collection.contains(obj) is called
        println("Yes: array contains ddd")
    else
        println("No: array doesn't contains ddd")
}

CommandLine Arguments ...

Stdin Inputs...

輸出畫面

OK

1 2 3 4 5 

Out: array has only 3 elements. x = 8

Yes: array contains aaa

No: array doesn't contains ddd