Floating PointImplementations
For general use, the C language on most computers defines a float floating-point storage type, 4 bytes long, that handles approximately 6-7 decimal digits of mantissa and an exponent between -38 and +38
The C language double floating-point storage type, 8 bytes long, handles approximately 17-18 decimal digits of mantissa and an exponent between -308 and +308
Remember: Bits are bits. The same bit pattern may be a signed or unsigned integer, a character, or a floating-point number, depending on how it is used.