Question: I understand how mostly everything works in a loop in Java but I came to a realization that I am failing to understand one thing which is The Order a Loop Operates.

Basically I am failing to understand this because of this simple but boggling piece of code that was displayed in my class, the code is displayed below.

```
public class Test {
    public static void main (String[] args) {
        int sum = 0;
        for (int k = 1; k < 10; k += 2)
        {
            sum += k;
            System.out.print(sum + " ");
        }
    }
}

```

The output the program puts out is 1 4 9 16 25

Now I understand how it repeats and spits out the numbers but how does it go about even creating 1. Now you can say it created 1 by taking k and adding it to sum but shouldn't k be equaling 3? 

It goes k = 1; This sets k equal to 1. k < 10; Checks if k is less than 10. Then the question is when k += 2; Shouldn't k now equal to 3 but instead sum is now somehow equal to 1 after this operation occurred of adding 2 to 1, 2 + 1 = 3 but 3 + 0 = 1? How does this even go about.

My rationalizing for this is that any program I thought was to interpret code line by line or uniformly and not jumping around.

Overall my question is, how is sum equal to 1 when k is actually equal to 3.

Answer: 
The sections of the for loop are run at different times.

1. The first section is run once at the start to initialize the variables.
2. The second is run each time around the loop at the START of the loop to say whether to exit or not.
3. The final section is run each time around the loop at the END of the loop.

All sections are optional and can just be left blank if you want.

You can also depict a for loop as a while loop:

```
for (A;B;C) {
    D;
}

```

is the same as:

```
A;
while (B) {
    D;
    C;
}

```
Let's break up your code. The keyword for just means loop. It will start @ 1 and continue as long as k is less than 10. It will also increase by `k+=2`. To translate, it means `k = k +2`

Inside the loop `sum = sum + k`. It will then print the value that sum has plus a space.

```
k = 1, sum = 1
k = 3, sum = 4
k = 5, sum = 9
k = 7, sum = 16
k = 9, sum = 25

```

and keep repeating. Let me know if you still have trouble grasping this concept