Reference group in regular expression - Java Regular Expressions

Introduction

\1 refers to the first capture group.

Demo Code

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
  public static void main(String[] args) {
    Pattern pattern = Pattern.compile("\\w(\\d)-\\w\\1");
    Matcher matcher = pattern.matcher("r2-d2");
    if (matcher.matches())
      System.out.println("Match.");
    else/*from w w  w  .  j  a v a2  s .  com*/
      System.out.println("Does not match.");
  }

}

• Previous
• Next

Related Tutorials

• Use split method to split a string based on delimiters that match a regular expression
• Let a user enter the area code for a phone number with or without parentheses.
• | symbol defines an 'or' operation
• Create regular expression for U.S. phone numbers with an optional area code
• Using parentheses to group characters