Convert from octal(base 8) to decimal(base 10) and then to character.
public class OctalToAscii { public static void main(String[] args){ // Note: octal is base 8. String sOctal = "355"; // Convert Octal(base8) to decimal(base 10). Integer iOctal = Integer.parseInt(sOctal, 8); System.out.println(iOctal); // Output: 237 // Cast decimal to its corresponding ASCII value. char cOctal = (char)iOctal.intValue(); System.out.println(cOctal); // Output í } }