Verification and Validation

import java.util.*;
public class ValidationVerification
{
    public static void main(String[] args) {
        Scanner userInput = new Scanner(System.in);

        /*type check
        A TYPE CHECK checks that the data entered is of a given data type,
        for example number of brothers or sisters would be an integer (whole number).
        */
       while (true){
       System.out.println("Enter age.");
       try{
           int age = userInput.nextInt();
           break;
       }
       catch (InputMismatchException e)
       {
           System.out.println("You may only enter integers as an age. Try again.");
           userInput.next();
       }
}
 while (true){
       System.out.println("Enter age.");
       String age=userInput.next();
       try{
          int num=Integer.parseInt(age);
           break;
       }
       catch (NumberFormatException e)
       {
           System.out.println("You may only enter integers as an age. Try again.");
           System.out.println(e.getMessage());
           userInput.next();
       }
    }

    int []scores={3,22,99,56,77};
    try{
    for (int i=0;i<6; i++){
        System.out.println(scores[i]);
    }
}
    catch(ArrayIndexOutOfBoundsException e) {
         System.out.println("Array is out of Bounds"+e);
    }

        /*length check
       Checks that the input contains a certain amount of characters
        */
       System.out.println("Enter name.");
       String name = userInput.next();
       while (true){
       if (name.length()<3||name.length()>15){
           System.out.println("You may only enter names between 3 and 15 characters,try again.");
           name = userInput.next();
       }
       else{
       break;
       }
}

        /*range check
        A RANGE CHECK checks that only numbers within a specified range are accepted. For
        example percentage marks between 0 and 100 inclusive.
        */
       System.out.println("Enter percentage score.");
       int score = userInput.nextInt();
       while (true){
       if (score<0||score>100){
           System.out.println("You may only enter scores from 0 to 100, try again.");
           score = userInput.nextInt();
       }
       else{
       break;
       }
}

        //presence check - checks that something has been input (not left blank)
       System.out.println("Enter surname.");
       String surname = userInput.next();
       while (true){
       if (surname.length()<0){ //this won't work in the java terminal window.
           System.out.println("You cannot leave surname blank");
           surname = userInput.next();
       }
       else{
       break;
       }
}

        //format check - checks that the input follows a specific format.
       System.out.println("Enter phone number.");
       String phone = userInput.next();
       String pattern1="010";
       String pattern2="011";
       String pattern3="017";
       int invalidChars=0;
       if (phone.substring(0,3).equals(pattern1)||phone.substring(0,3).equals(pattern2)||phone.substring(0,3).equals(pattern3)){
           if (phone.length()==11){
               //character check
               for (int x=0; x<phone.length(); x++){
                  if (Character.isDigit(phone.charAt(x))){
                    }
                  else{
                      invalidChars+=1;
                    }
                }
               if (invalidChars>0){
                   System.out.println("The numnber contains"+invalidChars+"invalid characters");
            }
            }else{
                System.out.println("invalid length");
            }
        }else{
    System.out.println("invalid format, must begin 010,011 or 017");
}

        //verification
       System.out.println("Enter email address.");
       String email1 = userInput.next();
       System.out.println("Enter email again.");
       String email2 = userInput.next();
       if (email1.equals(email2)){
           System.out.println("Email matched, they have been verified.");
    }else{
        System.out.println("Emails do not match, they have NOT been verified.");
    }
}
}