How to get blocks to Drop something when hit

Hello, I am making a Minecraft like game and would like blocks to drop an item when broken. But how do I do it? I already have a destroy block function but not to where it would break. Is there any way I can incorporate them together? or do I have to make a completely new thing.

Code that Destroys block: https://hastebin.com/jogiyewada.cs

I would also like different blocks to drop different things. Thanks.