Question

I need a java method that takes in an integer and then increments it and gives you the respective alpha character. Something like this:

public String getAlpha(Integer number) {
   ...
}

So if I pass the number value equal 0 then it should increment and return the letter a. If I pass it 25 then it should return the letter z. If I pass it the number 26 then it should return aa. If I pass it the number 27 then it should return ab and so on.

The alpha’s pretty much simulate the way excel sheet columns are represented, all I need to do is get the alpha value from a method by passing it a number. There is no set limit except the String that gets returned from getAlpha must be a maximum of 15 chars and a minimum of 1 char.

Answer 1

I believe this will do what you want, I don’t know if it can be done more efficiently:

static void printCode(int code) {
  final StringBuilder buffer = new StringBuilder();
  do {
    final int digit = (code - 1) % 26;
    buffer.insert(0, (char)(digit + 'a'));
    code = (code - digit - 1) / 26;
  } while (code > 0);
  System.out.println(buffer);
}