Strings in Java

Tom Dunne

Hi All,

I'm have a fairly basic problem with a Java program I am writing. I have a string (which is read in from the keyboard). I want to get the ASCII value of each member of the string (e.g. A=65, B=66, etc). I am sure it's relativly easy to do.

I am a getting a little frustrated with searching java.sun.com (22,941 hits for my query).

Thanks,

TD.

DeadBankClerk

From: Java.Sun.com > Java API

byte[] getBytes()
Encodes this String into a sequence of bytes using the platform's default charset, storing the result into a new byte array.

davej

First convert the string to a char[] array using the toCharArray() method. Then you can cast each char in the array to an int using a loop. The int values will correspond to the ascii code...

davej

Hobbes

ASCII? Wouldn't it be Unicode?

Tom Dunne

Er, I'm not sure.

What I'm trying to do is implement ROT13 to encode a message. When the user enters a word, each letter is rotated by 13 characters to A becomes M, B becomes N, etc.

Pretty basic stuff, but this is my first foray into Java. Give me 8051 assembly language any day.

TD.

seamus

I'll try this out myself in a sec......

But just try

String.getBytes();

and for each byte, just add 0xd, then convert it back to a string....

{edit:

Yep, do as above, then cast each byte into a char and add to the string. E.g.

byte[] b;
String s = "";
for(int i = 0; i < b.length; i++) {
     s += (char)(b[i] + 0xd);
}

And hey presto! Spaces always become "?" so you might want to remove them using a tokenizer (or a randomizer)

Tom Dunne

Thanks Seamus, I'll give it a try within the next few days.

Hobbes

I believe you have to use s.charAt() so as to handle Unicode.

eg.

   String s = "This is a test";

   for (int i = 0; i < s.length(); i++)
      char rot = s.charAt(i);

      if ((rot >= 'A') & (rot <= 'Z')) {
         System.out.print((char) rot + 13);
      }
   }

You get the general idea.