floating point value

[Cathy Song]

Technically speaking, what does floating point value mean?
Is double a "floating point value" also? If yes, why?
For example, if a method returns a floating point value, is it safe to assume that it is returning a float?
Thanks,
Cathy.

[Damien Howard]

a floating point value is always a decimal eg 1.15, 10.0, 0.93, -25.0
It can be either double or float. The term floating point has to do with the fact that the decimal point "floats" it is not always in the same place. With a non-floating point value such as int the decimal point is always in the same place, to the right of all the values.
10 = non floating point
10.0 = floating point
A method that returns a floating point value returns either a float or a double, you do not have enough info to say for sure with just floating point value as the description.

[Cathy Song]

Hi Damien,
Thanks for clearing my doubt.
--Cathy.

[mike acre]

Basically you only have the 32 or 64 bits (with float & double) to play with to give a certain level of accuracy. If the decimal point was fixed, a lot of the time it would make the most significant bits redundant eg 000010.567 so the point 'floats' as far left as it can ie 10.5672345, and thus gives the greatest accuracy using the remaining bits. It actually manages this my having an exponent part to the bit pattern, which tells it the magnitude of the number.