Question

So I have a string I would like to parse and I can not get my regular expression to work. I am using https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/RegExp as my regular expression guide.

I would like my regular expression to match on any of the following symbols.

+ - * % / 

My code as follows. Input String: D[1]+D[0]. Should print true…but prints false.

String tmp = "D[1]+D[0]";
if(tmp.matches("[\\+\\-\\*\\/\\%]"))
    System.out.println("true");
else
    System.out.println("false");

Any ideas?

Answer 1

This is because matches wants the entire string to be matched, not just any part of it.

You do not need to escape characters inside square brackets.

String str = "D[1]+D[0]";
Pattern p = Pattern.compile("[+-/*]");
Matcher m = p.matcher(str);
if (m.find()) {
    System.out.println("Found: " + m.group());
}