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()) }
}
}