How can I use a while loop in java to find the sum of all numbers between 0 and a given integer?

I'am happy to join the community. I have no prior experience to coding and I am currently experiencing my very first steps into java programming. Can someone please help me understand and solve the problem in the labs about the loop in java. Please find attached the screenshots of the labs.
Thank you for helping[Loops in java](https://i.stack.imgur.com/7FkEL.png)

What is the code for a while loop to get the sum of all numbers between 0 and end (exclusive)

Note that your while-loop is commented-out.

Here is a Java tutorial on while and do-while loops.
The while and do-while Statements (The Java™ Tutorials > Learning the Java Language > Language Basics).

In Java, to create a while-loop, you use the following structure.

while (i < end) {

}

To derive a sum of values, from i to an exclusive end, you can use the following.

sum = sum + i;
i = i + 1;

To return the sum value, you use

return sum;

All together the code for the whileExample method would be as follows.

int whileExample(int end) {
    int sum = 0;
    int i = 0;
    while (i < end) {
        sum = sum + i;
        i = i + 1;
    }
    return sum;
}