The group() method of Matcher Class is used to get the input subsequence matched by the previous match result.
Syntax:
public String group()
Parameters: This method do not takes any parameter.
Return Value: This method returns the String which is the input subsequence matched by the previous match.
Exception: This method throws IllegalStateException if no match has yet been attempted, or if the previous match operation failed.
Below examples illustrate the Matcher.group() method:
Example 1:
// Java code to illustrate end() method  import java.util.regex.*;  public class GFG {    public static void main(String[] args)    {          // Get the regex to be checked        String regex = "(G*s)";          // Create a pattern from regex        Pattern pattern            = Pattern.compile(regex);          // Get the String to be matched        String stringToBeMatched            = "GeeksForGeeks";          // Create a matcher for the input String        Matcher matcher            = pattern                  .matcher(stringToBeMatched);          // Get the current matcher state        MatchResult result            = matcher.toMatchResult();        System.out.println("Current Matcher: "                           + result);          while (matcher.find()) {            // Get the group matched using group() method            System.out.println(matcher.group());        }    }} |
Output:
Current Matcher: java.util.regex.Matcher[pattern=(G*s) region=0, 13 lastmatch=]
s
s
Example 2:
// Java code to illustrate end() method  import java.util.regex.*;  public class GFG {    public static void main(String[] args)    {          // Get the regex to be checked        String regex = "(G*G)";          // Create a pattern from regex        Pattern pattern            = Pattern.compile(regex);          // Get the String to be matched        String stringToBeMatched            = "GFG FGF GFG";          // Create a matcher for the input String        Matcher matcher            = pattern                  .matcher(stringToBeMatched);          // Get the current matcher state        MatchResult result            = matcher.toMatchResult();        System.out.println("Current Matcher: "                           + result);          while (matcher.find()) {            // Get the group matched using group() method            System.out.println(matcher.group());        }    }} |
Output:
Current Matcher: java.util.regex.Matcher[pattern=(G*G) region=0, 11 lastmatch=]
G
G
G
G
G
Reference: Oracle Doc
