没有打印出所有书面陈述

Question

Sample run:

License Validator
Enter a last name: ab    bA
Enter a last name: ab bA
Enter year of birth: a12w
Enter year of birth: 1979
Enter driver's license number: A123-4567-9801-23
Consistent

My code is: import java.util.Scanner; public class five {

    private static String getLastName(Scanner sc)
    {
         System.out.println("License Validator");
        System.out.print("enter last name: ab bA");
        String lastname=sc.nextLine().trim();
        if(lastname.length()==0)
            lastname=getLastName(sc);
        int numspaces=0;
        for(int i=0;i<lastname.length();i++)
            {
                if(Character.isSpace(lastname.charAt(i)))
                    {
                        numspaces++;
                    }
                else if(!Character.isLetter(lastname.charAt(i)))
                    {
                        lastname=getLastName(sc);
                    }

                if(numspaces>2)
                    {
                        lastname=getLastName(sc);
                    }      
            }
        return lastname;
    }
    private static boolean Character(char charAt) {
        return false;
    }
    public static String getYearOfBirth(Scanner sc)
    {
        System.out.print("Enter year of birth: 1979");
        String year=sc.nextLine().trim();
        if(year.length()==0)
            year=getYearOfBirth(sc);
        try
        {
        int yearint=Integer.parseInt(year);
            if(yearint<1900||yearint>1999)
            {
                year=getYearOfBirth(sc);
            }  
        }
        catch(NumberFormatException e)
        {
            year=getYearOfBirth(sc);
        }
        return year;
    }
    public static String getlicensenumber(Scanner sc)
    {
        System.out.print("Enter driver's license number:");
        String licencenum=sc.nextLine().trim();
        if(licencenum.length()!=17||licencenum.length()==0)
        {
            licencenum=getlicensenumber(sc);
        }
        String arr[]=licencenum.split("-");
        if(arr.length!=4)
        {

            licencenum=getlicensenumber(sc);
        }
        if(Character.isLetter(arr[0].charAt(0)))
        {
            if(Character.isLowerCase(arr[0].charAt(0)))  
            {

                    licencenum=getlicensenumber(sc);
            }
        }
        else
        {

            licencenum=getlicensenumber(sc);
        }
        try
        {
            Long.parseLong(arr[0].substring(1)+arr[1]+arr[2]+arr[3]);
        }
        catch(NumberFormatException e)
        {
            licencenum=getlicensenumber(sc);
        }
        return licencenum;
    }
    public static void main(String[] args)
    {
        Scanner sc=new Scanner(System.in);
        String lastname=getLastName(sc);
        String yearOfBirth=getYearOfBirth(sc);
        String licensenumber=getlicensenumber(sc);
        if(licensenumber.substring(0, 1).equalsIgnoreCase(lastname.substring(0, 1))&&(licensenumber.substring(8, 9)+licensenumber.substring(10, 11)).equals(yearOfBirth.substring(2)))
            {
                System.out.println("Consistent");
            }
        else
            System.out.println("fraudulent");
    }

 }

It will only output:

License Validator
Enter last name:

I'm confused as to why the other string methods are not outputting? Also, the if statement for lastName has crossed out the "isSpace" and says that it is depreciated.

Answer 1

It will only print the prompt for year after you enter the last name and the prompt for license number after you input the year.

Scanner.nextLine() scans all the user input till he hits enter. So only when you hit enter will it stop reading for input and move on to the next line of code.

And since you have put in validation checks for each input, it will not accept your input till the entered value is valid. Once you enter a valid input and hit enter it will move on to the next method.

EDIT:

  else if (!Character.isLetter(lastname.charAt(i))) {
            lastname = getLastName(sc);
  }

The above part in your code checks if the character is a letter or not and prints the prompt again if it is not a letter/alphabet. So, every time it encounters a space in your last name, it fails the check and prompts you to enter the last name again.