how to round of decimal answer

Question

1.00/5 (1 vote)

See more:

How to round of answer

C#

decimal a = decimal.Parse(Label20.Text);
        decimal b = decimal.Parse(Label15.Text);
        decimal c = b - a;

        Label22.Text = c.ToString();

Posted 9-Jul-15 19:57pm

Unni R

Add a Solution

Comments

Sergey Alexandrovich Kryukov 10-Jul-15 2:30am

Why? I'm not joking. In all questions about rounding, no one really needed rounding, they needed rounded string representation of the number. Most likely, you too. Mathematical rounding not only superfluous, it can be an extra danger, accidentally leading to critical loss of precision.
—SA

[no name] 20-Jul-15 12:08pm

"Nobody" needs rounding, really?
I have a BOM, where e.g. each component is in %:
The Display is e.g.
# CONC ID
1 0.0000 Mat1

Not rounded (at the right time/place) it is unsure wheter CONC is now really 0 or maybe 0.0000001, which may come to effect as soon the amount for Mat1 Needs to be calculated for production....if 0 no Mat1, otherwhise Mat1 is needed.

Sergey Alexandrovich Kryukov 20-Jul-15 12:11pm

No nobody, but it's almost never needed. I don't mean sophisticated things like random number generators.

Probably, you miss the point: I mean directly use rounding. You need rounding, but usually, indirect, through formatting. As soon as you say "display", this is not rounding per se, this is getting formatted sting of rounded value. You never get intermediate rounded result of a numeric type, and this is good.

You will understand it if you read my answer and referenced articles properly.

—SA

[no name] 20-Jul-15 12:21pm

as you say "display":
But that is the point. The user sees "0.000" but the real value is maybe "0.00001". So for me rounding is very important, but a very dangerous and sometimes difficult thing to do it at the right time/place.

Sergey Alexandrovich Kryukov 20-Jul-15 12:30pm

I already explained that. Use proper formatting. Rounding won't help you.
—SA

[no name] 20-Jul-15 12:45pm

No you did not, at least not with the links in your answer. But discussing rounding can become an endless Story, so we do not Need to do this.

Only one part of the endless story ;)
https://en.wikipedia.org/wiki/Rounding[^]

Thank you for your effort (even if it sometimes seems pedantic) but I know you as an excellent teacher!

Sergey Alexandrovich Kryukov 20-Jul-15 14:07pm

You just need to understand it properly, learn format specifiers well enough. They will do proper rounding for you and leave you free from doing it yourself. Yes, rounding is a big problem, but it matters so much (can create accumulation of the rounding errors) only if you use it in intermediate results. Just don't do it, and you will be done.
—SA

3 solutions

Solution 3

C#

Math.Round(Convert.ToDecimal(Label20.Text)), 2);

OR

C#

double doubleNumber;
doubleNumber= 17843.1234;
doubleNumber.ToString("F2",CultureInfo.InvariantCulture));
// Displays 17843.12

Posted 20-Jul-15 1:33am

Uzzal Kanti Barua

Solution 1

Read the documentation : Decimal.Round Method (Decimal)[^]

Posted 9-Jul-15 20:18pm

Mehdi Gholam

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)

Sergey Alexandrovich Kryukov · Accepted Answer · 2015-07-09T20:33:00

Solution 2

Please see my comment to the question. I don't see where you need rounding. Rather, you need proper string formatting, to get rounded value. Please see:
https://msdn.microsoft.com/en-us/library/fzeeb5cd%28v=vs.110%29.aspx[^],
https://msdn.microsoft.com/en-us/library/0c899ak8%28v=vs.110%29.aspx[^].

—SA

Posted 9-Jul-15 20:33pm

Sergey Alexandrovich Kryukov

Updated 20-Jul-15 4:46am

v3

Comments

Sanket Saxena 20-Jul-15 8:13am

my +5 for the solution SA

Sergey Alexandrovich Kryukov 20-Jul-15 8:52am

Thank you, Sanket.
—SA