Scanner useDelimiter() method in Java with Examples

useDelimiter(Pattern pattern)

The useDelimiter(Pattern pattern) method of java.util.Scanner class sets this scanner’s delimiting pattern to the specified pattern.

Syntax: 

public Scanner useDelimiter(Pattern pattern)

Parameter: The function accepts a mandatory parameter pattern which specifies a delimiting pattern.

Return Value: The function returns this scanner.

Below programs illustrate the above function:

Program 1:

Java

// Java program to illustrate the useDelimiter(Pattern Pattern)
// method of Scanner class in Java

import java.util.*;
import java.util.regex.Pattern;

public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {

        String s = "Geeksforgeeks has Scanner Class Methods";

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

        // print a line of the scanner
        System.out.println("Scanner String: \n"
                           + scanner.nextLine());

        // display the old delimiter
        System.out.println("Old delimiter: "
                           + scanner.delimiter());

        // change the delimiter of this scanner
        scanner.useDelimiter(Pattern.compile(".ll."));

        // display the new delimiter
        System.out.println("New delimiter: "
                           + scanner.delimiter());

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

Output:

Scanner String: 
Geeksforgeeks has Scanner Class Methods
Old delimiter: \p{javaWhitespace}+
New delimiter: .ll.

useDelimiter(String pattern)

The useDelimiter(String pattern) method of java.util.Scanner class Sets this scanner’s delimiting pattern to a pattern constructed from the specified String.

Syntax:

public Scanner useDelimiter(String pattern)

Parameter: The function accepts a mandatory parameter string pattern which specifies a delimiting pattern.

Return Value: The function returns this scanner.

Below programs illustrate the above function:

Program 1:

Java

// Java program to illustrate the useDelimter(String Pattern)
// method of Scanner class in Java

import java.util.*;

public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {

        String s = "Geeksforgeeks has Scanner Class Methods";

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

        // print a line of the scanner
        System.out.println("Scanner String: \n"
                           + scanner.nextLine());

        // print the old delimiter
        System.out.println("Old Delimiter: "
                           + scanner.delimiter());

        // change the delimiter
        scanner.useDelimiter("Wor");

        // print the new delimiter
        System.out.println("New Delimiter: "
                           + scanner.delimiter());

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

Output:

Scanner String: 
Geeksforgeeks has Scanner Class Methods
Old Delimiter: \p{javaWhitespace}+
New Delimiter: Wor

Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#useDelimiter(java.lang.String)