Need help to split in Java

Question

I have this problem in java. When I write 3/5 + 3 it returns 18/5 and it's correct but if I write 3/5/ + 3 it returns 18/5 instead of error

    public static RatNum parse(String s) {
    int x = 0;
    int y = 0;
    String split[] = s.split("/");
    if (split.length == 2) {
        x = Integer.parseInt(split[0]);
        y = Integer.parseInt(split[1]);
        return new RatNum(x, y);
    } else if (split.length == 1) {
        x = Integer.parseInt(s);
        return new RatNum(x);
    } else {
        throw new NumberFormatException("Error");
    }
}

What is the string you feed into the function? Just "3/5" and "3/5/", or the whole "3/5 + 3"? The latter seems improbable, because it would crash on parseInt. — Humungus
– Humungus, Commented Nov 30, 2013 at 11:46

Domi · Accepted Answer · 2013-11-30 12:55:17Z

1

This is because the regex parser prunes empty entries: "3/5/".split("/").length will return 2.

You can avoid empty entries by making sure it does not start or end with "/":

while (s.startsWith("/"))
  s = s.substring(1);

while (s.endsWith("/"))
  s = s.substring(0, s.length()-1);

Or throw an error if there is an empty entry:

if (s.startsWith("/") || s.endsWith("/"))
   throw new SomeError();

edited Nov 30, 2013 at 12:55

answered Nov 30, 2013 at 11:48

Domi

24.9k19 gold badges104 silver badges133 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Lukas Knuth Over a year ago

See the documentation

Collectives™ on Stack Overflow

Need help to split in Java

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related