Error message

I can compile just fine but when I try and run the program I get this message. Can someone please help me out with this. "Exception in thread "main" java.lang.NullPointer.Exception

class BooksTestDrive {
public static void main(String[] args) {
Books[] myBooks = new Books[3];
myBooks[0].title = "The Grapes of wrath";
myBooks[1].title = "The Java";
myBooks[2].title = "The Java cookbook";
myBooks[0].author = "bob";
myBooks[1].author = "joe";
myBooks[2].author = "deb";
int x = 0;

while (x < 2) {
System.out.print(myBooks[x].title);
System.out.print("by");
System.out.print(myBooks[x].author);
x = x+1;
}
}
}

Originally posted by Rick Rod:
I can compile just fine but when I try and run the program I get this message. Can someone please help me out with this. "Exception in thread "main" java.lang.NullPointer.Exception

class BooksTestDrive {
public static void main(String[] args) {
Books[] myBooks = new Books[3];
myBooks[0].title = "The Grapes of wrath";
myBooks[1].title = "The Java";
myBooks[2].title = "The Java cookbook";
myBooks[0].author = "bob";
myBooks[1].author = "joe";
myBooks[2].author = "deb";
int x = 0;

while (x < 2) {
System.out.print(myBooks[x].title);
System.out.print("by");
System.out.print(myBooks[x].author);
x = x+1;
}
}
}

You stack trace will tell you more. Specifically, it will point to the line myBooks[0].title = "The Grapes of wrath";
You can use this stack trace to diagnose your issue using a systematic approach (no brain cells required). That approach is document here.

Look for a section

// An object reference referring to an object called 'o'.
// All elements of the array are initialized to null.
Object[] o = new Object[10];
// Dereferencing a null object reference (the fourth element of the array referred to by 'o').
String s = o[4].toString();

Thank you for your documentation it was a big help.
I figured out that I had to refer the array's to the object and it worked.

on a side note how would I get the wording to be equally spaced out. right now the outcome is
"the grapes of wrathbybobthe java byjoethe java cookbookbydeb"
I want to have it as
"the grapes of wrath by bob the java by joe the java cookbook by deb"
Now you can really tell I am a begginer.

I figured it out, trial an error,
it works if you just keep trying.

I would never use a while loop and guess about the length of myBooks!

for (int x = 0; x < myBooks.length; x++) {
System.out.println(myBooks[x].title + " by " + myBooks[x].author);
}