Limits on Floating-Point Constants
Visual Studio 2015
The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.
The latest version of this topic can be found at Limits on Floating-Point Constants.
Microsoft Specific**
Limits on the values of floating-point constants are given in the following table. The header file FLOAT.H contains this information.
Limits on Floating-Point Constants
| Constant | Meaning | Value |
|---|---|---|
| FLT_DIGDBL_DIGLDBL_DIG | Number of digits, q, such that a floating-point number with q decimal digits can be rounded into a floating-point representation and back without loss of precision. | 6 15 15 |
| FLT_EPSILONDBL_EPSILONLDBL_EPSILON | Smallest positive number x, such that x + 1.0 is not equal to 1.0 | 1.192092896e–07F 2.2204460492503131e–016 2.2204460492503131e–016 |
| FLT_GUARD | 0 | |
| FLT_MANT_DIGDBL_MANT_DIGLDBL_MANT_DIG | Number of digits in the radix specified by FLT_RADIX in the floating-point significand. The radix is 2; hence these values specify bits. | 24 53 53 |
| FLT_MAXDBL_MAXLDBL_MAX | Maximum representable floating-point number. | 3.402823466e+38F 1.7976931348623158e+308 1.7976931348623158e+308 |
| FLT_MAX_10_EXPDBL_MAX_10_EXPLDBL_MAX_10_EXP | Maximum integer such that 10 raised to that number is a representable floating-point number. | 38 308 308 |
| FLT_MAX_EXPDBL_MAX_EXPLDBL_MAX_EXP | Maximum integer such that FLT_RADIX raised to that number is a representable floating-point number. | 128 1024 1024 |
| FLT_MINDBL_MINLDBL_MIN | Minimum positive value. | 1.175494351e–38F 2.2250738585072014e–308 2.2250738585072014e–308 |
| FLT_MIN_10_EXPDBL_MIN_10_EXPLDBL_MIN_10_EXP | Minimum negative integer such that 10 raised to that number is a representable floating-point number. | –37 –307 –307 |
| FLT_MIN_EXPDBL_MIN_EXPLDBL_MIN_EXP | Minimum negative integer such that FLT_RADIX raised to that number is a representable floating-point number. | –125 –1021 –1021 |
| FLT_NORMALIZE | 0 | |
| FLT_RADIX_DBL_RADIX_LDBL_RADIX | Radix of exponent representation. | 2 2 2 |
| FLT_ROUNDS_DBL_ROUNDS_LDBL_ROUNDS | Rounding mode for floating-point addition. | 1 (near) 1 (near) 1 (near) |
Note that the information in the above table may differ in future implementations.
END Microsoft Specific
Show: