CH02 코틀린기초 - 맵이터레이션

맵 이터레이션

val binaryCharMap = TreeMap<Char, String>()

for (c in 'A'..'F') {
	val binary = Integer.toBinaryString(c.toInt())
    binaryCharMap[c] = binary
    // java style binaryCharMap.put(c, binary)
}

for ((ch, bi) in binaryCharMap) {
	println("C ${ch} : Binary ${bi}"
}

val list = arrayListOf("a", "b", "c")

for((idx, e) in list.withIndex()) {
	println("Index ${idx} Element ${e}")
}

in으로 범위 검사

 

fun isLetter(c: Char) = c in 'a'..'z' || c in 'A'..'Z'

fun isNotDigit(c: Char) = c !in '0'..'9'

fun recongnize(c:char) = 
	when (c) {
		in '0'..'9' -> "digit"
        in 'a'..'z', in 'A'..'Z' -> 'Alpabet'
        else -> "Unknon char ${c}"
	}


"Kotlin" in "Java".."Scala" 
// "Java" <= "Scala" && "Kotlin" <= "Scala"


>>> printlin("Kotlin" in "Java".."Scala")
>>> true