1. joinToString() https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/join-to-string.html joinToString - Kotlin Programming Language kotlinlang.org println(listOf('a', 'b', 'c').joinToString(seperator="", prefix="(", postfix=")") --> (abc) 2. Debug Keystore 생성 $ keytool -genkey -v -keystore debug.keystore -storepass android -alias androiddebugkey -keypass android -keyalg RSA -keysize..
