Java Scanner match() Method

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Description

The java Scanner match() method returns the match result of the last scanning operation performed by this scanner. This method throws IllegalStateException if no match has been performed, or if the last match was not successful.

Declaration

Following is the declaration for java.util.Scanner.match() method

public MatchResult match()

Parameters

NA

Return Value

This method returns a match result for the last match operation

Exception

IllegalStateException − If no match result is available

Getting Last Match Result of a Scanner on a String Example

The following example shows the usage of Java Scanner match() method to get the match result for last match operation. We've created a scanner object using a given string. We've checked a string pattern "Hello" to be present in the strin using hasNext() method and using match(), the result is printed. Then we printed the string using nextLine() method and then scanner is closed using close() method.

package com.tutorialspoint;

import java.util.Scanner;

public class ScannerDemo {
   public static void main(String[] args) {

      String s = "Hello World! 3 + 3.0 = 6 ";

      // create a new scanner with the specified String Object
      Scanner scanner = new Scanner(s);

      // check if next token is "Hello"
      System.out.println(scanner.hasNext("Hello"));

      // find the last match and print it
      System.out.println(scanner.match().group());

      // print the line
      System.out.println(scanner.nextLine());

      // close the scanner
      scanner.close();
   }
}

Output

Let us compile and run the above program, this will produce the following result −

true
Hello
Hello World! 3 + 3.0 = 6 

Getting Last Match Result of a Scanner on User Input Example

The following example shows the usage of Java Scanner match() method to get the match result for last match operation. We've created a scanner object using System.in class. We've checked a string pattern "Hello" to be present in the strin using hasNext() method and using match(), the result is printed. Then we printed the string using nextLine() method and then scanner is closed using close() method.

package com.tutorialspoint;

import java.util.Scanner;

public class ScannerDemo {
   public static void main(String[] args) {

      // create a new scanner with the System Input
      Scanner scanner = new Scanner(System.in);

      // check if next token is "Hello"
      System.out.println(scanner.hasNext("Hello"));

      // find the last match and print it
      System.out.println(scanner.match().group());

      // print the line
      System.out.println(scanner.nextLine());

      // close the scanner
      scanner.close();
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Hello World
true
Hello
Hello World

Getting Last Match Result of a Scanner on a Properties File Example

The following example shows the usage of Java Scanner match() method to get the match result for last match operation. We've created a scanner object using a File properties.txt. We've checked a string pattern "Hello" to be present in the strin using hasNext() method and using match(), the result is printed. Then we printed the string using nextLine() method and then scanner is closed using close() method.

package com.tutorialspoint;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class ScannerDemo {
   public static void main(String[] args) throws FileNotFoundException {

      // create a new scanner with a file as input
      Scanner scanner = new Scanner(new File("properties.txt"));

      // check if next token is "Hello"
      System.out.println(scanner.hasNext("Hello"));

      // find the last match and print it
      System.out.println(scanner.match().group());

      // print the line
      System.out.println(scanner.nextLine());

      // close the scanner
      scanner.close();
   }
}

Assuming we have a file properties.txt available in your CLASSPATH, with the following content. This file will be used as an input for our example program −

Hello World! 3 + 3.0 = 6

Output

Let us compile and run the above program, this will produce the following result −

true
Hello
Hello World! 3 + 3.0 = 6