I am in a big confussion. While loops

Question

1. {
static void Main(string[] args)
{
int num = 0;
while(num++ < 6)
Console.WriteLine(num);
}
it execute 6 times. begin with 1 and end with 6.
2.
int num = 0;
while(num < 6)
{
Console.WriteLine(num);
num++;
}
it execute 6 times. but begin with 0 and end with 5.

what is different between this two. Please explain me in brief.

Answer 1

in the first code when value of x reaches 5 it is checked whether it's incremented value that is 6 is smaller than 6 which is false and thus it does not execute but other when x reaches 5 it's checked if x that is 5 still is less than that its true and therefore execute one more time.

Answer 2

Thanks a lot Sandeep Chatterjee. I really liked your Ans.