CODEWITHSUNDEEP
javastringinteger
cryptiblinux
cryptiblinux

Reputation: 27

Getting the charAt for two characters

I'm trying to split a string into two-character blocks. I then want to find the position of the two characters in a character array. How do I do this in Java

    for (int i = 0; i < message.length(); i += 2) {

        // Split the message into substrings of 2
        String splitMessage = message.substring(i,+ i+2);
        System.out.println(splitMessage);
        //
        for (int j = 0; j < splitMessage.length(); j++) {
            int plainTxtCh = charSet.indexOf(splitMessage.charAt(j));
            System.out.println(plainTxtCh);
        }

which returns

xy
23
24
ed
4
3
dd
3
3

what I want to do is pair the two numbers together. So for example after xy, I would have one integer '2324' instead of two seperate integers. Thanks.

EDIT: I want every two letters to be grouped into one integer according to their position in the alphabet string I made, so 'ed' = 43 dd='33' etc.

Upvotes: 1

Views: 2202

Answers (3)

Cootri
Cootri

Reputation: 3836

Maybe you should try this:

String charset = "abc";
String message = "abcabcabca";

char[] msgArr = message.toCharArray();
for (int i = 0; i < msgArr.length; i += 2) {
    System.out.println(msgArr[i] + "" + (i == msgArr.length - 1 ? "" : msgArr[i + 1]));
    System.out.println(charset.indexOf(msgArr[i]) + "" + (i == msgArr.length - 1 ? "" : charset.indexOf(msgArr[i + 1])));
}

The output is:

ab
01
ca
20
bc
12
ab
01
ca
20

Works with both odd and even message length :)

Upvotes: 0

Rafal Iwaniak
Rafal Iwaniak

Reputation: 161

You can use Pattern. Remember that when you'd like to find digits in your string, use:

Matcher m = Pattern.compile("\\d+").matcher(yourString);

Or you can delete "enter" between digits. Use this pattern to find you divided digits:

Pattern p = Pattern.compile("(\\d+)(\\s)(\\d+)");

Upvotes: 0

Rabbit Guy
Rabbit Guy

Reputation: 1892

Change the inner for loop to this following:

for (int j = 0; j < splitMessage.length(); j++){
    int plainTxtCh = charSet.indexOf(splitMessage.charAt(j));
    System.out.print(plainTextCh);
}
System.out.println();

Upvotes: 1

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