Why my empty array still inserts into the my db table?

[eluser]towki[/eluser]
[quote author="Aken" date="1352441721"]Because you're defining your array with a key => value structure, the array is not considered empty. You'll need to go through and check the values of $data1 in order to see if it's "empty".[/quote]

I only got this way of inserting data in the user guide.Could you tell me the other way to define my array? So when the array is empty will be considered empty.