Getting substring by regex

[Christine Mayer]

Hi, I got a String that is composed of digits, white space, numbers
and other characters.
Example: 03... London (first two digits of post code, plus 3 dots for
the remaining digits).

I want to go through the String and search for the first occurrence of
a letter (A-Za-Z).
Then I want the String from this point on, excluding the "post code
String" containing only numbers, whitespace and dots.
The class String seems to have a "split(regex) function, but this
didn't work for me.

Any idea how this could be done?

Thanks in advance,

Christine

 

[Joshua Cranmer]

Hi, I got a String that is composed of digits, white space, numbers
and other characters.
Example: 03... London (first two digits of post code, plus 3 dots for
the remaining digits).

I want to go through the String and search for the first occurrence of
a letter (A-Za-Z).
Then I want the String from this point on, excluding the "post code
String" containing only numbers, whitespace and dots.
The class String seems to have a "split(regex) function, but this
didn't work for me.

Any idea how this could be done?

Thanks in advance,

Christine

Look at matching for regex:
http://java.sun.com/j2se/1.5.0/docs/api/java/util/regex/Pattern.html

 

[Christine Mayer]

Well, I know the Pattern class, but I don't think it could help here.
You were probably thinking of the split function (Which seems to do
just the same the String.split function does)

In the API, it gives the following example:

The input "boo:and:foo", for example, yields the following results
with these parameters:

Regex Limit Result
: 2 { "boo", "and:foo" }
: 5 { "boo", "and", "foo" }
: -2 { "boo", "and", "foo" }
o 5 { "b", "", ":and:f", "", "" }
o -2 { "b", "", ":and:f", "", "" }
o 0 { "b", "", ":and:f" }


However, in all these examples there is only one character as "regex.
While in my case I need a whole String as regex, if found, I need to
chop of this part from the String...

 

[Joshua Cranmer]

Well, I know the Pattern class, but I don't think it could help here.
You were probably thinking of the split function (Which seems to do
just the same the String.split function does)

You obviously did not read the link I gave you. On that page, under the
heading "Groups and capturing":
Capturing groups are so named because, during a match, each
subsequence of the input sequence that matches such a group is saved.
The captured subsequence may be used later in the expression, via a back
reference, and may also *be retrieved from the matcher once the match
operation is complete.* [ My emphasis. ]

 

[SadRed]

Well, I know the Pattern class, but I don't think it could help here.
You were probably thinking of the split function (Which seems to do
just the same the String.split function does)

You obviously did not read the link I gave you. On that page, under the
heading "Groups and capturing":
Capturing groups are so named because, during a match, each
subsequence of the input sequence that matches such a group is saved.
The captured subsequence may be used later in the expression, via a back
reference, and may also *be retrieved from the matcher once the match
operation is complete.* [ My emphasis. ]

You don't nedd capturing groups for this simple task.
------------------------------------------
import java.util.regex.*;

public class ChristineMayer{

public static void main(String[] args){

String[] texts = {"03... London",
"18... Christine",
"35... Mayer",
"77... Bagdad"};

String regx = "[A-Za-z]+"; // substring comosed of Eng. alphabet

Pattern pat = Pattern.compile(regx);
for (String s : texts){
Matcher mat = pat.matcher(s);
while (mat.find()){
System.out.println(mat.group());
}
}
}
}
---------------------------------------

 

[Roedy Green]

The class String seems to have a "split(regex) function, but this
didn't work for me.

see http://mindprod.com/jgloss/regex.html

See the section on matching vs finding.

You might find this easier to do by a char by char stepping through
the string. Write yourself a method that categorizes a char and
returns an enum, e.g. ALPHA, NUM, DOT, OTHER to use is the loop.

see http://mindprod.com/jgloss/finitestate.html