a java programm with try and catch mechanism

/*
 * Some Comments on your source code by CTO
 * Grades is the class name it should begin with capital to fit conventions (camel case assumed)
 * Put spaces between code blocks like for loops and related code groups
 * grade = grade/10; is more readble than grade /= 10; its better in terms of self documentation
 * 
 * ===Try and catch==
 * Unaweka simba (code) inayotarajia kurusha 'exceptions' katika try block na baada
 * tu ya simba unayotaka inaswe inapotokea tatizo weka catch block!
 * i.e
 * try{....} catch(Exception e){..do something with e}
 * 
 * ==Commandline argument==
 * These are received and added to array in order added to exe i.e
 * java yourProgram p1 p2 p3
 * will give args array of
 * args[0]==>p1
 * args[1]==>p2
 * args[3]==>p3
 * Check example before in first code block of main
 * Use them as you want
 * See this link for details: http://www.codeproject.com/Tips/419749/Working-with-command-line-arguments-in-Java
 */

import java.util.Scanner;

public class Grades {

    public static void main(String[] args) {
       
        try{ //in case anything happened in code tell us why!
           //parse commandline args
           for (int i = 0; i < args.length; i++) {
                System.out.println(args[i]);
            }
           
           //rest of your code
            int grade = 0;

            for (int i = 0; i < 10; i++) {
                grade += validInt("Enter mark " + (i + 1) + "[0-100]: ", 0, 100);
            }

            grade = grade/10;

            System.out.print("You earned a " + grade + " ");
            if (grade >= 70 && grade <= 100) {
                System.out.println("A");
            }         
            else if (grade >= 60 && grade <= 69) {
                System.out.println("B+");
            } 
            else if (grade >= 50 && grade <= 59) {
                System.out.println("B");
            } 
            else if (grade >= 40 && grade <= 49) {
                System.out.println("C");
            } 
            else if (grade >= 30 && grade <= 39) {
                System.out.println("D");
            } 
            else {
                System.out.println("E");
            }
       }
       catch(Exception e)
       {
           System.out.println(e.getMessage());// tells you what went wrong
       }
    }

    public static int validInt(String prompt, int min, int max) {
        Integer result = null;
        
        while (true) {
            System.out.print(prompt);
            Scanner in = new Scanner(System.in);
            
            if (in.hasNextInt()) {
                result = in.nextInt();
            }
            
            if (result != null && result >= min && result <= max) {
                return result;
            } 
            else {
                System.out.println("Invalid Number!...enter again");
            }
        }
    }
}