Integer value rounding in VB.NET

Question

I have code as below:

Dim num1 As Integer
Dim num2 As Integer

num1 = 12.5
num2 = 17.5

When I output the values, I get this:

num1: 12
num2: 18

If 12.5 become 12, is 17.5 supposed to be 17?

Or if 17.5 become 18, is 12.5 supposed to be 13?

I'm pretty new in Visual Basic, and it's hard to find any reference on this.

Answer 1

This is because VB use banker’s rounding (round-to-even rule) as stated in Integer documentation

In this method, when the remainder at the rounding position is .5, that number is rounded up when the number before it is odd, and rounded down when the number before it is even.

For example, using round-to-even rule

2.5 round down to the even number 2.0, 
3.5 would round up to the even number 4.0