Kotlin基础 if,for,while语句

val num = 1
if(num==1){
println("monday");
}else if(num==2){
println("tsd");
}else{
println("nono");
}
if (x == 3 || x == 4 || x == 5)
println(""+x + "春季")
else if (x == 6 || x == 7 || x == 8)
println(""+x + "夏季")
else if (x == 9 || x == 10 || x == 11)
println(""+x + "秋季")
else if (x == 12 || x == 1 || x == 2)
println(""+x + "冬季")
else
println(""+x + "月份不存在")

if (x > 12 || x < 1)
println(""+x + "月份不存在")
else if (x >= 3 && x <= 5)
println(""+x + "春季")
else if (x >= 6 && x <= 8)
println(""+x + "夏季")
else if (x >= 9 && x <= 11)
println(""+x + "秋季")
else
println(""+x + "冬季")

val x = 3
when (x) {

4 -> {
println("a")
println("b")
}
5 ->{
println("hello");
}

6 -> println("b")
2 -> println("c")
else -> {
println("d")
println("a")
println("b")
}
}

val a = 4
val b = 2

val ch = '+'

when (ch) {
'-' -> println(a - b)
'+' -> println(a + b)
'*' -> println(a * b)
'/' -> println(a / b)
else -> println("feifa")
}

for(x int 0..2){//变量名 数据类型 通过..字符标识区间
println(x);
}
var y =0;//如果是val就不可以了，var代表的是变量，val代表是常量不可改变
while(y<3){
println(y):
y++
}