The priority in multiple order

How orders in multiple order command are placed? In multiple order, here, we define a batch or an array of orders. My question is which one is placed in order book first and which one is the second and so on? Does it go to order book according to the array? That is, first order(0) goes to order book, then order(1) and so on? Or it is random?
What if I want the order(0) be executed first and then order(1) be executed?
Thank you.

Hi, there is no guarantee of the sequence of them.