Regex for capital letters

[Kudret Serin]

Hi,
How can I get the index of 4th capital letter in a string with using pattern and matcher ?
Actually I need the regex.
Thanks for any help.
Greetings

[Rob Spoor]

There are (at least) two ways for this:
1) simply look for one capital letter, then use Matcher.find() 4 times
2) use a regular expression that immediately finds the 4th capital letter. You will most likely need a capturing group for that.

[Kudret Serin]

Thanks for the reply but as I said I need the regex

[David Newton]

In general answers are not simply handed out here--what have you come up with so far?

[Campbell Ritchie]

There are all sorts of details in the Java™ Tutorials. We don't simply give answers like that; we expect you to do the work and we'll have a look at it.

[Kudret Serin]

I have following code but i am not sure if there is a better way especially with better regex so I do not need variable i and the loop.

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


class test 
{
	public static void main(String[] args) 
	{	Console console = System.console();

		Pattern pattern = Pattern.compile("[[A-Z].[A-Z].[A-Z].[A-Z]]");
		Matcher matcher = pattern.matcher("This is my First Application, However");

		int i = 0;
		while (matcher.find()) {
			i++;			
			if( i==4) console.format("I found the text \"%s\" starting at " +
			   "index %d and ending at index %d.%n",
				matcher.group(), matcher.start(), matcher.end());

		}

	}
}  

[Henry Wong]

2) use a regular expression that immediately finds the 4th capital letter. You will most likely need a capturing group for that.

Of course, as soon as I read this... I wondered if it was possible to do this without a capturing group. And thought of two ways....

1. You can use a zero length look-behind for the beginning and the first three capital letters -- then you can take the start() of the match. (look behinds are non-capturing).

2. You can do the regex that makes sures that it matches the 4th capital letter as the last part of the match, and then use end() minus one on the match.

But I agree. Using a capturing group is probably easiest.

Henry

[Henry Wong]

I am actually a bit rusty with character classes, but I think that this....

Pattern pattern = Pattern.compile("[[A-Z].[A-Z].[A-Z].[A-Z]]");  

Is the same as this....

Pattern pattern = Pattern.compile("[A-Z.]");  

So, basically, you are trying to match a single character, that is either a capital letter or a period.

Anyway, your solution is as Rob describes...

1) simply look for one capital letter, then use Matcher.find() 4 times

You just need to get rid of the period, as you don't want to match that.

Henry