JAVA regex for "String, String."

Question

Given string "Neil, Gogte., Satyam, B.: Introduction to Java"

I need to extract only "Neil, Gogte." and "Satyam, B." from given string using regex how can I do it?

If this is the case, I would choose `substring()` over regular expression. — Aniket Sahrawat, Mar 14 '18 at 15:51

score 0 · Answer 1 · answered Mar 14 '18 at 16:04

You can use matcher to group

String str = "Neil, Gogte., Satyam, B.: Introduction to Java";
Pattern pattern = Pattern.compile("([a-zA-Z]+, [a-zA-Z]+\\.)");
Matcher matcher = pattern.matcher(str);

while(matcher.find()){
    String result = matcher.group();
    System.out.println(result);
}

score 0 · Answer 2 · answered Mar 14 '18 at 16:08

You can use the following regex to split the string. This matches any locations where ., exist:

(?<=\.),\s*

(?<=\.) Positive lookbehind ensuring what precedes is a literal dot character .
,\s* Matches , followed by any number of whitespace characters

See code in use here

import java.util.*;
import java.util.regex.Pattern;

class Main {
    public static void main(String[] args) {
        final String s = "Neil, Gogte., Satyam, B.: Introduction to Java";
        final Pattern r = Pattern.compile("(?<=\\.),\\s*");
        String[] result = r.split(s);
        Arrays.stream(result).forEach(System.out::println);
    }
}

Result:

Neil, Gogte.
Satyam, B.: Introduction to Java

score 0 · Answer 3 · answered Mar 14 '18 at 18:35

You might use this regex to match your names:

[A-Z][a-z]+, [A-Z][a-z]*\.

In Java:

[A-Z][a-z]+, [A-Z][a-z]*\\.

That would match

[A-Z] Match an uppercase character
[a-z]+ Match one or more lowercase characters
, Match comma and a whitespace
[A-Z] Match an uppercase character
[a-z]* Match zero or more lowercase characters
\. Match a dot

Demo Java

JAVA regex for "String, String."

3 Answers3