Issue with regex expression parameter supplied to String split method.

I created a small test program below to to test the String split function. Its not working as I would expect it to work.

I expect the program to print:
Parts of the myString = #if
Parts of the myString = ABC
Parts of the myString= CCC
Parts of the myString = DDD

However, the program generates:
Parts of the myString = #if
Parts of the myString = ABC
Parts of the myString =
Parts of the myString =
Parts of the myString =
Parts of the myString = CCC
Parts of the myString =
Parts of the myString =
Parts of the myString =
Parts of the myString = DDD

Also, if I replace '#if ABC && CCC || DDD" with #if ABC & CCC | DDD", the program still generates the same results.

Furthermore, I realize | is a special character, but I get an compile time error if I change it to \|{2}.

Could someone please enlighten me. Thanks, Stephen

Code:

---

public class TestRegex {

    /**
    * @param args the command line arguments
    */
    public static void main(String[] args) {
 
        String regexString = "[()!&{2}|{2} ]" ;

        String myString = "#if ABC && CCC || DDD";

        String[] myStringArray = myString.split(regexString);

        for (String parts : myStringArray)
        {
            System.out.println("Parts of the myString = " + parts);
        }

    }
}

---

Your regex splits on every char contained in your square brackets, so it should be no surprise that you're getting the result you see. Why not instead use a String that holds variable amount of whitespace in front and behind, and then in parenthesis has a choice of space, or && or || (the latter escaped)? When I do this, my result is:


Parts of the myString = #if
Parts of the myString = ABC
Parts of the myString = CCC
Parts of the myString = DDD

For example...

Code:

---

String regex2 = "\\s*( |&{1,2}|\\|{1,2})\\s*";

---

Do you mean something like this?: String regexString = "[\\s*( &&\\|\\|)\\s*]"

For that expression my program returns:
Parts of the myString = #if
Parts of the myString = ABC
Parts of the myString = &&
Parts of the myString = CCC
Parts of the myString = ||
Parts of the myString = DDD

If I use String regexString = "[\\s*( &{2}\\|\\|)\\s*]", I get the same result as before.

Also, using a single escape character before | (e.g. \|) shows up as an error.

I just noticed you posted the regex, so you can disregard post #4.

Your problem is that you're using the square brackets where you shouldn't. Those are for extracting a single character only when you want a complete String.

Fantastic! That works. Thanks.

no problem.