Scanner, nextInt() -- what if somebody enters a string?

Question

How can i detect if the user enters a string? When somebody enters a string it causes some errors.
my code.
int iVar = input.nextInt();
if (iVar == 1)
          System.out.println("option 1");
else if (iVar == 2)
          System.out.println("option 2");
else if (iVar == 3)
          System.out.println("option 3");
else if (iVar == 4)
          System.out.println("option 4");
else // any integer
          System.out.println("wrong");
}if i entered a string, it causes an error
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:819)
at java.util.Scanner.next(Scanner.java:1431)
at java.util.Scanner.nextInt(Scanner.java:2040)
at java.util.Scanner.nextInt(Scanner.java:2000)
at compro1_nested_if_else_statement.main(nested_if_else_statement.java:32)
How will i detect that? for numbers (int) it is working fine.

Answer 1

something like this has worked for me:
        System.out.print("Please enter a number: ");
        while (!input.hasNextInt())
            input.nextLine();
            System.out.println("Please enter only Integer input");
        int iVar = input.nextInt();