Description |
The NaN constant provides a standard undetrmined number value for assigning to floating point variables.
It allows the floating point number to be treated as unassigned.
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Related commands |
Infinity |
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Floating point value of infinite size |
IsInfinite |
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Checks whether a floating point number is infinite |
IsNaN |
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Checks to see if a floating point number holds a real number |
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Example code : Assign NAN to a number and then test using IsNaN |
var
float : Double;
begin // Set the number to an invalid number float := NaN; // Equivalent to 0.0/0.0
// Although an invalid number, we can still display it
WriteLn('float = '+FloatToStr(float));
// And we can test to see if it is a valid number
if IsNaN(float)
then WriteLn('float is not a number')
else WriteLn('float = '+FloatToStr(float));
end;
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Show full unit code |
float = NAN
float is not a number
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