Regular expression for finding brackets

[Fred Victa]

How would I write a regular expression that would match "[" or "]" ?

[Bora Sabrioglu]

import java.io.*;
import java.util.regex.*;

class regex{
    public static void main(String[] args) throws IOException{
	  String string = "a4 0x12 5b _x_ 05[]6 092 0X5g 0X7Fa";
	  Pattern p = Pattern.compile("[\\[\\]]");
	  Matcher m = p.matcher(string);
	  while(m.find())
		System.out.println(m.start() + " " + m.group());
    }
}

[Fred Victa]

Bora Sabrioglu wrote:

import java.io.*;
import java.util.regex.*;

class regex{
    public static void main(String[] args) throws IOException{
	  String string = "a4 0x12 5b _x_ 05[]6 092 0X5g 0X7Fa";
	  Pattern p = Pattern.compile("[\\[\\]]");
	  Matcher m = p.matcher(string);
	  while(m.find())
		System.out.println(m.start() + " " + m.group());
    }
}

Thank you. That works.

[Bora Sabrioglu]

you're welcome.... just remember that metacharacters and strings don't mix too well... thats why you have to escape them twice (as in \\[)

[fred rosenberger]

well...that's not really a regular expression. It's a complete program. the regex would just be

[\[\]]

(i think...)

[Bora Sabrioglu]

fred rosenberger wrote:
[\[\]]

does not compile. (since "strings and metacharacters don't mix too well".)
Thats why you need to escape them :

[\\[\\]]

[fred rosenberger]

Bora Sabrioglu wrote:

fred rosenberger wrote:
[\[\]]

does not compile. (since "strings and metacharacters don't mix too well".)
Thats why you need to escape them :

[\\[\\]]

What do you mean "does not compile"? it's not being compiled. It is a regular expression. it stands alone. I've even tested it using the Regex Coach.

Of course, I am being hyper-literal here. the OP asked for "the regex". Not "how do I write a regex in a java program that does this".

To beat a dead horse: There is a difference between "the regex" and "how the regex must be represented in a java program".