Pattern toString() method in Java with examples

The Pattern class of the java.util.regex package is a compiled representation of a regular expression.

The toString() method of this class returns the string representation of the regular expression using which the current Pattern was compiled.

Example1

import java.util.Scanner;
import java.util.regex.Pattern;
public class Example {
   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());
      //Verifying whether match occurred
      if(pattern.matcher(input).find())
         System.out.println("Given String contains digits");
      else
         System.out.println("Given String does not contain digits");
   }
}

Output

Enter input string
This 7est contain5 di9its in place of certain charac7er5
Compiled regular expression: (\d)
Given String contains digits

Example 2

import java.util.regex.Pattern;
public class Example {
   public static void main(String args[]) {
      String regex = "Tutorialspoint$";
      String input = "Hi how are you welcome to Tutorialspoint";
      Pattern pattern = Pattern.compile(regex);
      Matcher match = pattern.matcher(input);
      int count = 0;
      if(match.find())
         System.out.println("Match found");
      else
         System.out.println("Match not found");
      System.out.println("regular expression: "+pattern.toString());
   }
}

Output

Match found
regular expression: Tutorialspoint$