Why is my number being rounded incorrectly?

Posted by izb on Stack Overflow See other posts from Stack Overflow or by izb
Published on 2010-03-24T16:43:21Z Indexed on 2010/03/24 16:53 UTC
Read the original article Hit count: 266

Filed under:

c#

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floating-point

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floating-accuracy

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rounding

This feels like the kind of code that only fails in-situ, but I will attempt to adapt it into a code snippet that represents what I'm seeing.

float f = myFloat * myConstInt; /* Where myFloat==13.45, and myConstInt==20 */
int i = (int)f;
int i2 = (int)(myFloat * myConstInt);

After stepping through the code, i==269, and i2==268. What's going on here to account for the difference?

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