Kotlin常用內容（備忘）

介紹

本文是爲了kotlin常用的內容備忘，屬於筆記性質，不會有太多講解，適合kotlin初學者遺忘後幫助快速想起。會不定時常更新。

循環

爲了方便每行只是打一個log。

until不帶右側邊界。

object KotLinDemo {
    //常用循環
    fun cycle() {
        //普通循環
        for (i in 1..10) {Log.d("asdasdasd","i in 1..10 "+i.toString())}
        for (i in 1 until 9 step 2) {Log.d("asdasdasd","i until 9 step 2 "+i.toString())}
        for (i in 1 until 3) {Log.d("asdasdasd","i until 3 "+i.toString())}
        for (i in 10 downTo 3 step 1) { Log.d("asdasdasd","i downTo 3 "+i.toString()) }
        //迭代字符串，返回Char
        for (i in "qwe") { Log.d("asdasdasd","i in qwe "+i) }
        //普通while循環
        //while (3 < 10) {}
        //list迭代
        val alist = listOf<String>("a", "s", "d")
        //帶下標
        for ((index,value) in alist.withIndex()) { Log.d("asdasdasd",index.toString()+"  "+value) }
        //不帶下標
        for (i in alist) { Log.d("asdasdasd","i in alist "+i); }
        //map迭代
        val amap = mapOf(1 to 3, 4 to 2)
        for ((key, value) in amap) { Log.d("asdasdasd","map "+key.toString()+" "+value.toString()) }
    }
}