Exception handling

import java.util.*;

class program1
{
    public static void main(String args[])
    {
        Scanner scan = new Scanner(System.in);

        //If there's an error in the try{} block do catch{} block.
        //Instead of raising a weird error we simply just raise catch().
        try{
            System.out.print("Type in first number: ");
            scan.nextInt();
        }
        catch(Exception e)
        {
            System.out.print("Unable to complete.");
        }

        /*
         * In this case the user types a string
         * in to the input that scans the input.
         * That will raise an error. But instead of giving that
         * specific error we simply just execute the catch block.
         */
    }
}