Question

Let’s say I have a program which converts letters to numbers such that:

Input: abcd

Output: 1234

1. How can I convert abcd to 1234 efficiently
2. and how can I extract every individual char from the token

By the way, this is not homework. (this is for fun)

This is what I have so far:

public class Test {
public static void main(String[] args) throws IOException  {

    BufferedReader f = new BufferedReader(new FileReader("test.in"));

    PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("test.out.txt")));

    StringTokenizer st = new StringTokenizer(f.readLine());

    int i1 = Integer.parseInt(st.nextToken());

            // How can I convert this into integers? (where a = 1, b = 2, and c = 3)

            out.println(????);

        out.close();
        System.exit(0);                              

    }

}

Answer 1

Try this:

String s = "abcd";
StringBuilder sb = new StringBuilder();
for (char c : s.toCharArray()) {
    sb.append((char)(c - 'a' + 1));
}
// provided your string contains only lower case non-unicode (ASCII) characters.