9 May 2025   9:00:57.779 PM
 
CONSTANT_TYPE():
  FORTRAN90 version.
 
  Demonstrate that constants have a type.
 
  EXAMPLE 1:
 
  Print the value of
    1.0203040506070809 - 1.020304050607
 
     1.0203040506070809 - 1.020304050607 =    0.00000000    
 
  If single precision is the default, this will be 0.
 
  EXAMPLE 2:
  A constant has a type.
  If you do not specify one, one will be provided.
  Here, we assign a 32 decimal constant to single,
  double, and quadruple precision variables.
 
  Because we do not "type" the constant, we really
  only get the benefit of the first 8 or so decimals.
 
    a = 1.020304050607080910111213141516
    b = 1.020304050607080910111213141516
    c = 1.020304050607080910111213141516
 
   A =    1.02030408    
   B =    1.0203040838241577     
   C =    1.02030408382415771484      
 
  EXAMPLE 3:
  Use an exponent marker of "E", "D" or "Q" to indicate
  that your constant is single, double or quadruple
  precision.
 
  If the compiler does not like our specification,
  the constant is treated as single precision, and
  some of the information in the constant is discarded,
  with NO WARNING.
 
    a = 1.020304050607080910111213141516E+00
    b = 1.020304050607080910111213141516D+00
    c = 1.020304050607080910111213141516Q+00
 
   A =    1.02030408    
   B =    1.0203040506070808     
 
  EXAMPLE 4:
  Use an kind marker of "_rk4", "_rk8" or "_rk16" to indicate
  that your constant is single, double or quadruple
  precision.  Might work, might not.
 
    a = 1.020304050607080910111213141516_rk4
    b = 1.020304050607080910111213141516_rk8
    c = 1.020304050607080910111213141516_rk16
 
   A =    1.02030408    
   B =    1.0203040506070808     
   C =    1.02030405060708091009      
 
constant_type():
  Normal end of execution.
 
 9 May 2025   9:00:57.779 PM