the mantissa is the number before the exponent in scientific notation for example:
6.23512 X 10^31
the 6.23512 is the mantissa and 31 is the exponent
this is really a silly question though look it up on the web...

the mantissa is the number before the exponent in scientific notation for example:
6.23512 X 10^31
the 6.23512 is the mantissa and 31 is the exponent
this is really a silly question though look it up on the web...

If the above didn''t clarify the difference between floats and doubles, here''s a simpler explanation.

floats are data types that can contain fractional parts of a number, such as 123.456, whereas integers can only store whole numbers such as 123456. I''m sure you already knew that.

floats are 32 bits, or 4 bytes, long, and are acturate to approximately 7 digits. This can be a problem if you want to store data with more precision. Consider the following:

the number 123.456789123, when stored as a float would actually be 123.4568 (approx) - remember it''s only accurate to 7 digits. This is more apparent with largers numbers such as 123456789 - this would be stored as 123456800. You can see that it isn''t really that accurate. That''s where doubles come into play.

doubles are stored in 64 bits, or 8 bytes, and are accurate to 15 digits. so the number 123.456789123 would be stored correctly. Likewise would the number 123456789.

That''s all the is too it.

Regards

PS - I should tell you that all calculations in the CPU are done as doubles, then rounded down to floats (if using a float data type) when storing back in memory, so there is no speed difference from the CPU''s point of view. However, because doubles take up twice as much memory, it takes slightly longer to get the data from memory into the CPU.