String to Char, Char to String

https://kutar37.tistory.com/entry/%EC%9E%90%EB%B0%94-String%EC%9D%84-Char%EB%A1%9C-Char%EB%A5%BC-String%EC%9C%BC%EB%A1%9C-%EB%B3%80%ED%99%98%ED%95%98%EA%B8%B0

String.toCharArray()

String.valueOf(char[])

String to Char

String str = "abcd";
char[] arr = str.toCharArray();

Char to String

char[] arr = {'a', 'b', 'c', 'd'};
String str = String.valueOf(arr);