Hello,
what is the right way to declare locals.
Should we assign a value directly when declaring a local.
For example:
Function test
local aTemp := {}
or is local aTemp enough.
Can someone please explain the difference.
Thank you in advance and best regards
Otto
This is a simple declaration:
local aTemp
while this other is a declaration with initialization:
local aTemp := {}
In the simple declaration the value of aTemp is NIL. After the initialization the type of aTemp is array and its value is an empty array.
EMG
Hello Enrico,
Thank you.
But what are the advantages and disadvantages of these two.
With kind regards
Otto
local aTemp := {}
is equivalent to
local aTemp
aTemp = {}
The advantage is that the first form is more compact, I presume.
EMG
Hello Enrico,
I read that declaration with initialization should be 3%-40% more speedy in executing the program.
Could this be?
Thank you in advance
Otto
Teoretically, yes. But I doubt it would make any visible difference in real programs.
EMG
FUNCTION Main()
Local nI
Local nMax:= 1000000
Local nSec1, nSec2
Local cSec1, cSec2
nSec1:= Seconds()
FOR nI:= 1 TO nMax
  Local1()
NEXT
cSec1:= Str(Seconds()- nSec1, 10, 5)
nSec2:= Seconds()
FOR nI:= 1 TO nMax
  Local2()
NEXT
cSec2:= Str(Seconds()- nSec2, 10, 5)
MsgInfo("Mode 1: "+ cSec1+ Chr(13)+ Chr(13)+;
       "Mode 2:"+ cSec2, "Results")
RETURN NIL
STATIC FUNCTION Local1()
Local a:= {}
RETURN NIL
STATIC FUNCTION Local2()
Local a
a:= {}
RETURN NILThis is NOT a real program, it is a sample. Anyway, it shows two identical values here.
EMG
RETURN NIL
Local nMax:= 10000000
STATIC FUNCTION Local1()
Local a:= {}
Local b:= {}
Local c:= {}
Local d:= {}
Local e:= {}
Local c1:= ""
Local c2:= ""
Local c3:= ""
Local c4:= ""
Local c5:= ""Mr. Otto,
Try first call to Local2() and after call to Local1()
Regards
Hello,
I did this yesterday and the results are the same. Declaration with initialization seams faster.
Enrico is right that in a real world program you would not see any differences.
In the same source I read that there is also speed differences between passing values by reference or value.
Best regards
Otto