What do I ++ I mean in the while clause?

What is the meaning of I ++ I in while? what are the meanings of I ++ ii ++ !, This is simple. you can see the following example: int & nbsp; a & nbsp ;=& nbsp; 3; int & nbsp; B & nbsp ;=& nbsp; 0; int & nbsp; I & nbsp ;=& nbsp; 1. what do I ++ I mean?
++ I
I ++
+ I
I +

What do these four Mean? they are always confused!
------ Solution --------------------
This is very simple. you can see the following example:

Int a = 3;
Int B = 0;
Int I = 1;

B = ++ I + a; // first add I to 1, I equals 2, then add it to a, B = 2 + 3 = 5;
B = I ++ a; // The I value remains unchanged. First, it is added with a, B = 1 + 3 = 4; then I is added with 1, and I is equal to 2;

However, in the for statement, both the prefix and the post-fix are similar.