kotlin for 循环语句

//循环语句
fun main(args:String){
    for(arg in args){//循环1
        println(arg)
    }
    //循环2
    for ((index,value) in args.withIndex()){
        println("$index -> $value")
    }
    //循环2等价与
    for (indexValue in args.withIndex()){
        println("${indexValue.index}->${indexValue.value}")
    }
    //public data class IndexedValue<out T>(public val index: Int, public val value: T) 这一种类型 可以转换为(i,v)形式 因为data
    //变量值可以替换
    for ((i,v) in args.withIndex()){
        println("$i -> $v")
    }

    //自定义类型迭代
    val list = MyIntList()
    list.add(1)
    list.add(2)
    list.add(3)

    for(i in list){//有迭代器的都可以使用for循环
        println(i)
    }

    var x = 5
    while (x > 0){
        if(x == 5){
            break//跳出循环
        }
        if(x == 3){
            continue//跳过循环
        }
        println(x)
        x--
    }
    do{
        println(x)
        x--
    }while (x > 0)
}

class MyIterator(val iterator:Iterator<Int>){
    operator fun next():Int{
        return iterator.next()
    }
    operator fun hasNext():Boolean{
        return iterator.hasNext()
    }
}
class MyIntList{
    private val list = ArrayList<Int>()
    fun add(int:Int){
        list.add(int)
    }
    fun remove(int:Int){
        list.remove(int)
    }
    operator fun iterator():MyIterator{
        return MyIterator(list.iterator())
    }
}