Using Groups in Regular Expressions - Java Regular Expressions

Java examples for Regular Expressions:Group

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Description

Using Groups in Regular Expressions

Demo Code

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

public class Main {
  public static void main(String[] args) {
    // Prepare regular expression. A group of 3 digits followed by 7 digits.
    String regex = "\\b(\\d{3})\\d{7}\\b";
    String source = "1111111111, 1111111, and 1111111111";
    /*from  ww w .j av a  2  s . com*/
    // Compile the regular expression 
    Pattern p = Pattern.compile(regex);

    // Get Matcher object
    Matcher m = p.matcher(source);

    // Start matching and display the found area codes
    while(m.find()) {
      // Display the phone number and area code. 
      // group 1 captures first 3 digits of match, 
      // whereas group 0 will have the entire phone number. 
      // The matched text can be obtained using m.group() or m.group(0)
      String phone = m.group();
      String areaCode = m.group(1);
      System.out.println("Phone: " + phone + 
                         ", Area Code: " + areaCode);
    }
  }  
}

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