The information in this article applies to:
The information in this article is included in the documentation starting with Visual C++ 5.0. Look there for future revisions. SUMMARY
Floating point decimal values generally do not have an exact binary
representation. This is a side effect of how the CPU represents floating
point data. For this reason, you may experience some loss of precision, and
some floating point operations may produce unexpected results.
-or- MORE INFORMATIONMicrosoft uses the Institute of Electrical and Electronics Engineers, Inc. (IEEE) floating point format for floating point number representation. For information about the actual binary representation of floating point values in a CPU and how precision and accuracy are affected in a floating point calculation, please see the following articles in the Microsoft Knowledge Base: Q36068 INFO: IEEE Floating-Point Representation and MS Languages Q125056 INFO: Precision and Accuracy in Floating-Point Calculations Sample Code
The Output ResultThey are not equal. The value of c is 2.4679999352 or 2.468000.For EPSILON, you may use the constants FLT_EPSILON defined for float as 1.192092896e-07F or DBL_EPSILON defined for double as 2.2204460492503131 e-016. You need to include float.h for these constants. These constants are defined as the smallest positive number x, such that x+1.0 is not equal to 1.0. Because this is a very small number it is advisable that you employ user-defined tolerance for calculations involving very large numbers. REFERENCESFor information on other predefined constants, please see: Microsoft Developer Network: C Floating-Point Constants Microsoft Additional query words: 1.00 1.50 2.00 4.00 8.00 8.00c 9.00 9.10 10.00 floating point
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