Scanner ioException() method in Java with Examples

Last Updated : 11 Jul, 2025
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 
// 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 
// 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()
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