23. 문자열을 다루는 법

▷ length, lowercase(), uppercase(), split(“.”), joinToString(), startsWith(), endsWith(), isNullOrEmpy(), isNullOrBlank()

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fun main () {

var a = "apple.Pear.String"

println(a.length)

println(a.toLowerCase())

println(a.toUpperCase())

val b = a.split(".")

println(b)

println(b.joinToString())

println(b.joinToString(""))

println(b.joinToString("-"))

println(a.substring(6..9))

val nullString : String? = null

val emptyString = ""

val blankString = " "

val normalString ="ABC"

// String이 비어있는지 확인

println(nullString.isNullOrEmpty())

println(emptyString.isNullOrEmpty())

println(blankString.isNullOrEmpty())

println(normalString.isNullOrEmpty())

println(nullString.isNullOrBlank())

println(emptyString.isNullOrBlank())

println(blankString.isNullOrBlank())

println(normalString.isNullOrBlank())

println(a.startsWith("java"))

println(a.startsWith("apple"))

println(a.endsWith("kt"))

println(a.endsWith("tring"))

println(a.contains("Pear"))

}