C# - Math.Round

I am trying to understand how to round to the neares开发者_JS百科t tenths position with C#. For instance, I have a value that is of type double. This double is currently set to 10.75. However, I need to round and then truncate everything past the tenths position. In this case, I am seeking a value of 10.8. How do I round to the tenths position in C#?

Thank you!

Math.Round(yourNumber, 1)

The second parameter is number of decimal places to round to. In your case you want 1 decimal place as an end result.

You simply need to use the overload of Math.Round that takes the decimals parameter.

Math.Round(10.75, 1) // returns 10.8

Just for comparison:

Math.Round(10.75)    // returns 11
Math.Round(10.75, 0) // returns 11
Math.Round(10.75, 2) // returns 10.75

Since you Used Math.Round() in your title, I'm going to assume you've already tried the basic Math.Round(10.75,1) approach and it returns something you don't expect. With that in mind, I suggest looking at some of the different overloads for the function, specifically one that accepts a MidPointRounding enum:

http://msdn.microsoft.com/en-us/library/f5898377.aspx

Do you really need to round it, or can you just format it for printing but allow the variable itself to hold its precision? Something like:

decimal value = 10.75;
value.ToString ("#.#");

If you just want to "cut" everything after the first decimal, this shoudl work :

   return Math.Round(value * 10)/10