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Thread: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

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    Default There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.



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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    You forgot to post the full text of the error message and the code where the error happens.

    An arrayoutofbounds error happens when the index to an array goes past the end of the array.
    Remember array indexes range in value from 0 to the array length-1
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    Quote Originally Posted by Norm View Post
    You forgot to post the full text of the error message and the code where the error happens.

    An arrayoutofbounds error happens when the index to an array goes past the end of the array.
    Remember array indexes range in value from 0 to the array length-1
    here's the error:

    Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
    at cs213.photoAlbum.simpleview.CmdView.main(CmdView.j ava:22)

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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
    at cs213.photoAlbum.simpleview.CmdView.main(CmdView.j ava:22)
    If there is no first element at index 0, the array must have a size of 0. The code needs to test the array's length before trying to index into the array with an invalid index.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    Quote Originally Posted by Norm View Post
    If there is no first element at index 0, the array must have a size of 0. The code needs to test the array's length before trying to index into the array with an invalid index.
    right, the thing is I'm supposed to run it in command line mode and the arguments would be inputted before running the main class....
    like this:

    To add a new user:
    java cs213.photoAlbum.simpleview.CmdView adduser <user id> "<user name>"
    Output:
    created user <user id> with name <user name>

    I don't know how to change the code to wait for the user inputs then test it from there

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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    to wait for the user inputs
    What you posted looks like for the user giving the program input on the command line where the args on the command line are passed to the main() method.

    If you want to prompt the user for input and read the response use the System.out.println() method for the prompt and use one of the Scanner class's methods to read the reponse.
    Or use a JOptionPane method to show a message and get a response.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    I added this to my code, and it doesn't work.
                    int count = 0;
            	cs213.photoAlbum.model.backend.readPerUser();
     
                    //s.useDelimiter("\n");
     
            	System.out.println("Enter instruction");
            	Scanner input = new Scanner(System.in);
     
            	while(input.hasNext())
                {
                	count++;
                }
     
            	String a[] = new String[count];
     
     
                    if(a[0].equals("listusers")==true){
                            cs213.photoAlbum.model.backend.listUsers();
                    }

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    Super Moderator Norm's Avatar
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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    it doesn't work.
    Can you explain what "doesn't work" means?
    What does the code do when you execute it?
    What do you want it to do differently?

    What is the posted code supposed to do?
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    album.txt backend.txt controll.txt photo.txt user.txt CmdView.txt


    these are the files. I'm supposed to implement a code that is allows a user to sign in and edit their albums, and photos. Also we're supposed to edit the captions, and tags. What I added to the CmdView in the before reply "doesn't work" because it doesn't allow me to add a user or list the photos. I just need to get the code to work and allow me to run the code my partner has written

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    Super Moderator Norm's Avatar
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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    it doesn't allow me to add a user or list the photos.
    What happens when you execute the code?
    It looks like it prints out a message and waits for the user to enter something.

    Is the program supposed to read something from the user?

    What do want done with the data that the user enters?
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    I added the print statement and scanner to try to make the code work..but failed. The program is supposed to wait for the user to enter like:
    To add a new user:
    java cs213.photoAlbum.simpleview.CmdView adduser <user id> "<user name>"
    Output:
    created user <user id> with name <user name>
    Or:
    user <user id> already exists with name <user name>

    and other functions too.

    Say I wanted to add user, the user inputs the arguments of the user ID and user name. Then I take those arguments and save it and shows the existing photos under that name and albums.

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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    Have you read the API doc for the Scanner class to see what methods to use for reading Strings from a user's input? The method you are using only tests if input is available.
    Do you want to read a String from the user? If not, what do you want to read?
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    Scratch the scanner stuff I added before, and I have read the scanner API doc but I want to read in Strings from the user. I want to read in String array arguments, but in Java the arguments are inputted after the main class has started running.

    The User is supposed to type in the terminal the path and the specific function they want to do such as add user and the arguments are <userID> <"username">

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    Default Re: There's an arrayoutofbounds, but my partner coded this and he doesn't know whats wrong.

    arguments are inputted after the main class has started running.
    No they are put on the command line with the java command and the class name as you've shown in your posts. If there aren't any args passed to the main() method, then the program will have to ask the user for them and read them as discussed earlier.

    If the args MUST come from the command line, the program can test if they are there and if not, print out an error message to the user and exit.

    I'm done for tonight.
    If you don't understand my answer, don't ignore it, ask a question.

  15. The Following User Says Thank You to Norm For This Useful Post:

    cryslam (March 22nd, 2013)

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