FORTRAN 77 Language Reference

Double-Precision Exponent

A double-precision exponent consists of the letter D, followed by an optional plus or minus sign, followed by an integer.

A double-precision exponent denotes a power of 10. The value of a double-precision constant is the product of that power of 10 and the constant that precedes the D. The form and interpretation are the same as for a real exponent, except that a D is used instead of an E.

Examples of double-precision constants are:

$1.0D2.0 					Invalid-$ not allowed, error message
82					Not DOUBLE PRECISION-need decimal point or exponent
29,002.0D0 					Invalid-comma not allowed, error message
1.8D308 					Invalid-too large, machine infinity is used
1.0D-324 					Invalid-too small, some precision is lost

The restrictions are: