Truncate decimal in float

[edel_ong]

How do I truncate a float such that if i have 1.20001, i would want to have 1.2 only for display. How could I achieve this? Thank you very much!

[S Senthil Kumar]

If you just want the truncated value as a string, you can use the ToString method on the float instance, like

float f = 1.2001f;
string truncatedFloat = f.ToString("0.0");

If you want that value as a float, you could multiply it by 10x, where x is the number of digits of precision required, cast it to an int and divide by 10x again i.e 1.20001 * 10 = 12.0001 = 12 / 10 = 1.2

Regards Senthil [MVP - Visual C#] _____________________________ My Blog | My Articles | My Flickr | WinMacro

[edel_ong]

works perfectly well. Thanks!

[Guffa]

S. Senthil Kumar wrote:

If you want that value as a float, you could multiply it by 10x, where x is the number of digits of precision required, cast it to an int and divide by 10x again i.e 1.20001 * 10 = 12.0001 = 12 / 10 = 1.2

Note that this is not guaranteed to produce the exact value that you expect. A float only has a precision of seven digits, so the result may just as well be something like 1.19999 or 1.20001. And why not use Math.Round(f, 1)?

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[S Senthil Kumar]

Guffa wrote:

Note that this is not guaranteed to produce the exact value that you expect.

Agreed, I missed the fact that the floating point representation could screw up things. But if he already uses tolerance values when checking for equality among floats, this shouldn't matter, right?

Regards Senthil [MVP - Visual C#] _____________________________ My Blog | My Articles | My Flickr | WinMacro