How to round up an integer by c#?

Question

I want a function to round up an integer, like this
11 -> 20
12 -> 20
31 -> 40
39 -> 40
50 -> 50
what can i do ?

Welcome to Stack Overflow! Pure code-writing requests are off-topic on Stack Overflow -- we expect questions here to relate to specific programming problems -- but we will happily help you write it yourself! Tell us [what you've tried](https://stackoverflow.com/help/how-to-ask), and where you are stuck. This will also help us answer your question better. — WhatsThePoint, Dec 27 '17 at 08:50
`(source + 9) / 10 * 10` in case of non-negative numbers only; `(sourse + (source > 0 ? 9 : -9)) * 10 / 10` in general case; there's a possibility of the integer overflow if `source` is close to `int.MaxValue` or `int.MinValue` — Dmitry Bychenko, Dec 27 '17 at 08:53
you can make a function like this: static int roundAsYouWant(int num){ return num % 10 == 0 ? num : ((Convert.ToInt32(num / 10)) * 10) + 10; } — FarukT, Dec 27 '17 at 09:07

score -3 · Accepted Answer · edited Dec 27 '17 at 11:32

-3

You could do something like this:

var mod = (i % 10);
var result = mod > 0 ? (i + 10 - mod) : i;

edited Dec 27 '17 at 11:32

Nitesh Kumar

answered Dec 27 '17 at 08:53

Kamil Budziewski

2

You aren't only calculating `result`, you are also changing `i`. I guess that is an undesired side effect. – Patrick Hofman Dec 27 '17 at 08:59
@PatrickHofman exactly, I've changed it – Kamil Budziewski Dec 27 '17 at 11:32
1

Well, Nitesh changed it ;) . But it will do. Thanks. – Patrick Hofman Dec 27 '17 at 11:33
@PatrickHofman I've accepted his edit, because I wanted to make same edit :) – Kamil Budziewski Dec 27 '17 at 12:09

1 Answers1