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Thread: Problems with Code?

  1. #1
    Junior Member Sean137's Avatar
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    Default Problems with Code?

    import java.util.*;
    import java.lang.*;
    /**
     * To output whether a students chosen password is valid or not.
     * 
     * @author (Sean McGlone
     * @version (December 13, 2010)
     */
    class SemesterProject
    {
        public static void main(String[]args)throws Exception
        {
            Scanner scanReader = new Scanner(System.in);
            String password = "";
            boolean firstLoop = true;
            int length = 0;
            int passwordLength = 0;
            int countCaps = 0;
                System.out.println("This was made by Sean McGlone");
                System.out.print("Please enter a password consisting of 12 characters to be checked for validity:  ");
                    password = scanReader.nextLine ();
                    passwordLength = password.length ();
            do
            {
                try
                {
                    if (passwordLength == 12)
                    { 
                        System.out.println("Your pasword meets the length requirements");
                    }
                        else
                        {
                            throw new Exception ();
                        }
                }
                    catch (Exception ex)
                {
                    System.out.println("Please enter a valid password consisting of 12 characters:  ");
                    password = scanReader.nextLine ();
                }
            }
            while (firstLoop = true);
        }
    }

    When I run this code the loop keeps reiterating even if a 12 character word is input. The loop keeps saying to please reenter a valid password. Can someone please help?

    Thanks
    Sean


  2. #2
    Crazy Cat Lady KevinWorkman's Avatar
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    Default Re: Problems with Code?

    Hint: == != =

    And even when you fix that, when do you set firstLoop to false?

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    javapenguin (December 14th, 2010)

  4. #3
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    Default Re: Problems with Code?

    It looks like firstloop is never set to false.

    Great way for an infinite loop.

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    Default Re: Problems with Code?

    Also, it's

    while (firstLoop == true)

    anyway.

  6. #5
    Member DavidFongs's Avatar
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    Default Re: Problems with Code?

    it should be while(firstLoop){} because that helps avoid the assignment error that is present.

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    javapenguin (December 14th, 2010)

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    Default Re: Problems with Code?

    How about this:
    boolean firstLoop = false;
               while (firstLoop != true)
    {
                try
                {
    password = scanReader.nextLine ();
                    passwordLength = password.length ();
                    if (passwordLength == 12)
                    {
                        System.out.println("Your pasword meets the length requirements");
    firstLoop = true;
                    }
                        else
                        {
                            throw new Exception ();
    firstLoop = false;
                        }
                }
                    catch (Exception ex)
                {
                    System.out.println("Please enter a valid password consisting of 12 characters:  ");
     
                }
            }

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