将字母转换为数字

Question

假设我有一个将字母转换为数字的程序，如下所示：

输入：abcd

输出：1234

1. 如何高效地将abcd转换为1234
2. 以及如何从令牌中提取每个单独的字符

顺便说一下，这不是家庭作业。（这是为了好玩）

这是我到目前为止所拥有的：

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

尝试这个：

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.