Matcher useAnchoringBounds() method in Java with Examples

The java.util.regex.Matcher class represents an engine that performs various match operations. There is no constructor for this class, you can create/obtain an object of this class using the matches() method of the class java.util.regex.Pattern.

The anchoring bounds are used to match the region matches such as ^ and $. By default, a matcher uses anchoring bounds.

The useAnchoringBounds() method of this class method accepts a boolean value and, if you pass true to this method the current matcher uses anchoring bounds and if you pass false to this method it uses non-anchoring bounds.

Example 1

import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Trail {
   public static void main( String args[] ) {
      //Reading string value
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter input string");
      String input = sc.nextLine();
      //Regular expression to find digits
      String regex = ".*\\d+.*";
      //Compiling the regular expression
      Pattern pattern = Pattern.compile(regex);
      //Printing the regular expression
      System.out.println("Compiled regular expression: "+pattern.toString());
      //Retrieving the matcher object
      Matcher matcher = pattern.matcher(input);
      matcher.useAnchoringBounds(false);
      boolean hasBounds = matcher.hasAnchoringBounds();
      if(hasBounds) {
         System.out.println("Current matcher uses anchoring bounds");
      } else {
         System.out.println("Current matcher uses non-anchoring bounds");
      }
   }
}

Output

Enter input string
sample
Compiled regular expression: .*\d+.*
Current matcher uses non-anchoring bounds

Example 2

import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Sample {
   public static void main( String args[] ) {
      String regex = "^<foo>.*";
      String input = "<foo><bar>";//Hi</i></br> welcome to Tutorialspoint";
      Pattern pattern = Pattern.compile(regex);
      Matcher matcher = pattern.matcher(input);
      matcher = matcher.useAnchoringBounds(false);
      if(matcher.matches()) {
         System.out.println("Match found");
      } else {
         System.out.println("Match not found");
      }
      System.out.println("Has anchoring bounds: "+matcher.hasAnchoringBounds());
   }
}

Output

Match found
Has anchoring bounds: false