Numbers with commas

Here's a simple method to include commas after every third digit from the right:

public class Utilities{
  private static int startingPivot;
  private static final int INDENT = 3;

  public static StringBuffer decimalize(int input){
    String conv = Integer.toString(input);
    StringBuffer sb = new StringBuffer();

    int commaIndex = conv.length() / INDENT ; 
    int strLength = conv.length();

    startingPivot = (strLength) - (commaIndex * INDENT );
    if (startingPivot == 0) {
      startingPivot = INDENT ;
    }

    for (int index = 0; index < strLength; index++) {
      if (index == startingPivot) {
        sb.append(",");
        startingPivot = startingPivot + INDENT;
      }
      sb.append(conv.charAt(index));
    }
    return sb;
  }
}

You may try this code by making this method call

System.out.println(Utilities.decimalize(1234567890));

and the output is 1,234,567,890
NEAT :D