no still it would be [15,1]

hmmm ... how to explain ... you do give the number of elements with that declaration.

Let's see, 15,1 means that you 'create' 16 elements in the first dimension, each of this element can contain two values (second dimension), the Book title and it's author

say $array[5,0] contains the title of the 6th book and $array[5,1] it's author.

Hope I don't confuse it even more
_________________________