java中的switch
int test=1;
switch(test){
case 1:
break;
default:
break;
}
kotlin使用when代替java中的switch，但比switch强大的多
when(test){
var test:Int =0
when(test){
is Int,0 -> Log.e("tag","test is int and test=0")
1-> "test=1"
else -> Log.e("tag","test is nothing")
}
}
//可以作为表达式并返回结果
val x:String=""
val isString = when(x){
is String -> x is String
else -> false
}
for循环
java:
for(int i=0;i<10;i++){
}
kotlin:
for (i in 0..4){
}
var list = listOf("1","2","3")
//循环遍历
for (i in list){
//可以直接使用list中的item对象
i.length
}
list.forEach {
it.length
}
