A REAL(8) or DOUBLE PRECISION constant has more than twice the accuracy of a REAL(4) number, and greater range.
A REAL(8) or DOUBLE PRECISION constant occupies eight bytes of memory. The number of digits that precede the exponent is unlimited, but typically only the leftmost 15 digits are significant.
IEEE® T_floating format is used.
For more information, see General Rules for Real Constants.
Compatibility
CONSOLE STANDARD GRAPHICS QUICKWIN GRAPHICS WINDOWS DLL LIB
See Also: REAL, REAL(8) or DOUBLE PRECISION Constants, Data Types, Constants, and Variables
Examples
DOUBLE PRECISION varnam
DOUBLE PRECISION,PRIVATE :: zz
The following examples show valid and invalid REAL(8) or DOUBLE PRECISION constants:
| Valid | |
|---|---|
| 123456789D+5 | |
| 123456789E+5_8 | |
| +2.7843D00 | |
| -.522D-12 | |
| 2E200_8 | |
| 2.3_8 | |
| 3.4E7_8 | |
| Invalid | Explanation |
| -.25D0_2 | 2 is not a valid kind type for reals. |
| +2.7182812846182 | No D exponent designator is present; this is a valid single-precision constant. |
| 1234567890D45 | Too large for D_floating format; valid for G_floating and T_floating format. |
| 123456789.D400 | Too large for any double-precision format. |
| 123456789.D-400 | Too small for any double-precision format. |