Thread: Please explain to me what I am doing wrong?

Hello!
I am preparing for my exam. And I am doing some java exercises from the book. But here I have some problem. My answer does not match with the book's answer. Please explain what I am doing wrong.

here is the code:


public class EX5 {
public static void main (String [ ] args) {
int [ ] data = {6, 2, 5, 1, 10, 3, -3};
int result = 0;
for (int i = 2; i < data.length; i++) {
result = result + (data[i] - data[i-2]);
System.out.println("result = " + result);
}
}
}
the book answer is
result = -1
result = -2
result = 3
result = 5
result = -8
.

But my answer is :
-1
-1
5
2
-13

Best regards

Ok next time i'll post codes' as yo suggested.
Well, the book says that I have to give answer by myself without using computer.


I calculated by myself.
First I thought that " i " starts from 2. so result + data[2] - data [2-2]= 0+ 5 - 6 = -1
then i increasing by 1, right (i++)
result + data [3] - data [3-2]= 0 + 1 - 2 = -1
result + data [4] - data [4-2]= 0 + 10 - 5 = 5 and so on.

which is obviously wrong answer. I want to know what i am doing wrong though