Parsing some data

Question

Hi,
I want to parse a string which can contain x number of up/down arrows.
These are represented by the unicode codes of \u2191and \u2193. Now i need to extract the positions of all of these items and replace the text with spaces where an arrow appears.
What is the best way to do this. Im thinking of using the stringtokenizer and getting setting the delim for the up and down arrows. However once I have these tokens I cant fiqure a way to replace the original text with spaces where these appear.
Any good suggestions?
Thanks

Answer 1

If you know the number of arrows, you can use an array.
If you don't know the number, you can either use an array with the same size as the char array (worst case), or use a Vector/ArrayList. Perhaps make a class that can hold the position and direction:
class Arrow {
  public static final char UP = '\u2191'; // dunno if this is up or down char
  public static final char DOWN = '\u2193';
  private final int pos;
  private final char direction;
  public Arrow(int pos, char direction) {
    this.pos = pos;
    this.direction = direction;
  public int getPos() { return pos; }
  public String getDirection() {
    if (direction == UP)
      return "UP";
    return "DOWN";
ArrayList pos = new ArrayList();
for (int x = 0; x < s.length(); x++) {
  if (s.charAt(x) == '\u2191' || s.charAt(x == '\u2193') {
    System.out.print(" ");
    pos.add(new Arrow(x, s.charAt(x));
  } else {
    System.out.print(s.charAt(x);
    // this is not an arrow.
for (int x = 0; x < pos.size(); x++) {
  Arrow arrow = (Arrow)pos.get(x);
  System.out.println("Arrow at pos: "+arrow.getPos()+" direction: "+arrow.getDirection());
}