A method that returns the sum of all odd integers from 1 to n

Question

1.00/5 (1 vote)

See more:

Hello, I am a new java learner and I have got a problem where I can't execute the code. I am trying to return the sum of all odd integers from 1 to n, but I think my code is doing something wrong. It would be wonderful if you check my problems. Thank you so much.

What I have tried:

<pre>
public class Main
{
    public static void main(String[] args) {
        int n;
        int i;
        int sum = 0;
        System.out.println("The sum of odd integer is " + sum + ".");
        
}
public class oddSum
{
    public int sumOfOdd(int n) {
    int sum =0;
    if (n<1){
        return sum;
    }
    for (int i = 1; i <= n; i += 2){
        if (i % 2 != 0){
            sum = sum+i;
        }
    }
    return sum;
}
}

Posted 19-Sep-21 14:27pm

Sarrymint 123

Updated 19-Sep-21 20:29pm

Add a Solution

3 solutions

Solution 1

You never create an instance of your "oddSum" class, nor do you even try to call it's "sumOfOdd" method with any parameters.

All your code does is start the "main" method in your "Main" class, initialize three variables to zero and print a string with the value of "sum", which will always be zero since that's the only value you assign to it.

This is your class work. Debugging this is up to you. I've told you what you've done wrong. It's up to you to figure out how to fix it.

Posted 19-Sep-21 17:53pm

Dave Kreskowiak

Updated 19-Sep-21 17:54pm

v2

Comments

CPallini 20-Sep-21 2:26am

5.

Solution 3

As a sid note, did you try to write the sum of the first odd numbers on paper (or notepad)? Namely

1              =  1
1 + 3          =  4
1 + 3 + 5      =  9
1 + 3 + 5 + 7  = 16
...

Do you see a pattern?

Posted 19-Sep-21 20:29pm

CPallini

Comments

Sarrymint 123 20-Sep-21 17:46pm

Ohhh I see the pattern. Thank you so much!

CPallini 21-Sep-21 1:56am

You are welcome.

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Patrice T · Accepted Answer · 2021-09-19T20:09:00

Quote:
but I think my code is doing something wrong.

In fact, the wrong is that your is not trying to do the thing.
Your main do not use the sumOfOdd.

Your code do not behave the way you expect, or you don't understand why !

There is an almost universal solution: Run your code on debugger step by step, inspect variables.
The debugger is here to show you what your code is doing and your task is to compare with what it should do.
There is no magic in the debugger, it don't know what your code is supposed to do, it don't find bugs, it just help you to by showing you what is going on. When the code don't do what is expected, you are close to a bug.
To see what your code is doing: Just set a breakpoint and see your code performing, the debugger allow you to execute lines 1 by 1 and to inspect variables as it execute.

Debugger - Wikipedia, the free encyclopedia[^]

Mastering Debugging in Visual Studio 2010 - A Beginner's Guide[^]
Basic Debugging with Visual Studio 2010 - YouTube[^]

1.11 — Debugging your program (stepping and breakpoints) | Learn C++[^]

The debugger is here to only show you what your code is doing and your task is to compare with what it should do.