A single-precision REAL constant occupies four bytes of memory. The number of digits is unlimited, but typically only the leftmost seven digits are significant.
On Tru64 UNIX, Linux, WNT, and W9* systems, IEEE® S_floating format is used. On OpenVMS systems, either Compaq VAX F_floating or IEEE S_floating format is used, depending on the compiler option specified.
Examples
The following examples show valid and invalid REAL(4) constants:
| Valid | |
3.14159 | |
3.14159_4 | |
621712._4 | |
-.00127 | |
+5.0E3 | |
2E-3_4 | |
| Invalid | Explanation |
1,234,567. | Commas not allowed. |
325E-47
| Too small for REAL; this is a valid DOUBLE PRECISION constant. |
-47.E47
| Too large for REAL; this is a valid DOUBLE PRECISION constant. |
625._6
| 6 is not a valid kind for reals. |
100 | Decimal point missing; this is a valid integer constant. |
$25.00 | Special character not allowed. |
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