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Thread: Exception in thread "main" java.lang.NullPointerException

  1. #1
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    Default Exception in thread "main" java.lang.NullPointerException

    class Books{
    String title;
    String author;
    }
    class BooksTestDrive{
    public static void main(String [] args){
    Books[] myBooks=new Books[3];
    int x=0;
    myBooks[0].title="Harry Potter";
    myBooks[1].title="Angels and Demons";
    myBooks[2].title="Revolution 2020";
    myBooks[0].author="J.K.Rowling";
    myBooks[1].author="Dan Brown";
    myBooks[2].author="Chetan Bhagat";
    while(x<3){
    System.out.println(myBooks[x].title);
    System.out.print(" by ");
    System.out.print(myBooks[x].author);
    x=x+1;
    }
    }
    }
    Last edited by JavaPF; October 31st, 2011 at 06:50 AM. Reason: Use highlight tags!


  2. #2
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    Default Re: Exception in thread "main" java.lang.NullPointerException

    Your myBooks objects are not initialized. You need to call the constructor on each object inside the vector. eg. mybooks[0] = new Books();

    application context
    Last edited by daniel.j2ee; December 13th, 2011 at 04:59 PM.

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