1. Int
int a = 65;
System.out.println("Integer to Character : " + (char) a); //A
System.out.println("Integer to String : " + String.valueOf(a)); //65
2. char
char ch = '3';
char[] ch2 = {'a','b'};
System.out.println("Character to Integer : " + ((int) ch - '0')); //3
System.out.println("Character to String : " + String.valueOf(ch)); //3
System.out.println("Character to String : " + String.valueOf(ch2)); //ab
3. String
String s = "9";
String s2 = "123";
System.out.println("String to Integer : " + Integer.parseInt(s)); //9
System.out.println("String to Character : " + s.charAt(0)); //9
System.out.println("String to Character : " + Arrays.toString(s2.toCharArray())); // [1, 2, 3]