Scanner ioException() method in Java with Examples

The ioException() method of java.util.Scanner class returns the IOException last thrown by this Scanner’s underlying Readable. This method returns null if no such exception exists.

Syntax:

public IOException ioException()

Return Value: This function returns the last exception thrown by this scanner’s readable.

Below programs illustrate the above function:

Program 1:

// Java program to illustrate the
// ioException() method of Scanner class in Java
// without parameter

import java.util.*;

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

        String s = "gfg geeks!";

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

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

        // check if there is an IO exception
        System.out.println("" + scanner.ioException());

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

Output:

gfg geeks!
null

Program 2:

// Java program to illustrate the
// ioException() method of Scanner class in Java
// without parameter

import java.util.*;

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

        String s = "gopal dave!";

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

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

        // checks if there is an IO exception
        System.out.println("" + scanner.ioException());

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

Output:

gopal dave!
null

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