Convert Double to Real

[bernhard_LA 0]

what is the best method to convert a double value back into a real data type ? 

 

var
x : double ;
y : real ;


y: = x ;

 

what are  the risk's ? 

 

[Rollo62 538]

17 minutes ago, bernhard_LA said:

what are  the risk's ?

http://docwiki.embarcadero.com/Libraries/Sydney/en/System.Real

 

Maybe only issues in older versions, currently it should be equivalent.

[David Heffernan 2347]

Given this definition

type Real = Double;

I'd say you don't have much to fear.

 

Of course, this code doesn't compile.

1 hour ago, bernhard_LA said:

y: = x ;

Edited July 16, 2021 by David Heffernan

[A.M. Hoornweg 144]

I believe the old Turbo Pascal "Real" type is now called Real48 and exists only for compatibility purposes (i.e. if you need to read or write files with data in that format).  It is much slower than either Double or Single because it's not a native FPU format.