Multiple replace of literals by digits-CodePudding

I need to replace multiple literals by digits in a string like "FF432423FA112". "A"=0, "B"=1 etc. I've tried to do it in a loop like but it didn't work. Tried also with char array

String test = "FF432423FA112";
String[] letters = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
    for (int i=0; i<letters.length; i  ) {
        newStr = test.replace(letters[i],i);
    }

CodePudding user response：

That is because you forget to use newStr.replace, every time loop will generate the last test.replace copy character

        String test = "FF432423FA112";
        String[] letters = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
        String newStr = test;
        for (int i=0; i<letters.length; i  ) {
            newStr = newStr.replace(letters[i], i   "");
        }

        System.out.println(newStr);

CodePudding user response：

If given string is "FF432423FA112" and the expected output is "5543242350112" considering to replace only alphabets and retain number as is, below code is an example.

public class Main {
    public static void main(String[] args) {
        String test = "FF432423FA112";
        String letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        StringBuilder output = new StringBuilder();
        int value = 0;
        for (int i=0; i<test.length(); i  ) {
            char c = test.charAt(i);
            if(Character.isDigit(c)) {
                value = Character.getNumericValue(c);
            } else {
                value = letters.indexOf(c);
            }
            output.append(value);
        }
        System.out.println(output);
    }
}