cfloat Function


Verifies whether the value of a floating-point variable is valid. Returns 0- VALID if the floating point value is OK, and 1- INVALID if the floating-point value is invalid.


cfloat(byref num as real) as valid_invalid

See Also:

strtof, ftostr




Variable to check.


Floating-point calculations can lead to invalid result (#INF, -#INF errors, as per IEEE specification). When your application is in the debug mode you will get a FPERR exception if such an error is encountered. In the release mode the Virtual Machine won't generate an exception, yet your application may need to know if a certain floating-point variable contains correct value. This is where cfloat function comes handy.


** Tibbo Basic **

dim r1 as real
dim v as invalid_valid

dim r1=10E30
v=cfloat(r1) 'v will return 0- VALID
r1=r1*10E20 'at this point you will get FPERR exception if you are in the debug mode
v=cfloat(r1) 'v will return 1- INVALID