Hi guys

A question that I have had for a long time:

Suppose I have the variable

list:TStringList

and I want to iterate through the items through the items in list.

Between the construction:

For i := 0 to list.Count - 1 do
begin;
  commands
end;

And the construction

j := list.Count - 1;
For i := 0 to j do
begin;
   commands
end;

Which would be the most efficient?

I ask because I have the impression that in the first construction it will be necessary to generate code to determine the value list.Count - 1 at each iteration of the For loop.

Greetings from S?o Paulo - Brazil

Ar? Ricardo
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Ar? Ricardo Ody wrote

[...] Between the construction: For i := 0 to list.Count - 1 do

In FPC the for-loop differs from a while-loop, as the for-loop fetches the start and end value only once.

Mattias

Matthieu Giroux 13 Rue Fr Tanguy PRIGENT A.15 - 35000 RennesT?l : 09 61 37 01 82 - 06 44 733 008 http://www.liberlog.fr

For i := 0 to list.Count - 1 do
begin;
? commands
end;
with list dofor i:=0 to count-1 doBegin? LText := Strings [i];

Ar? Ricardo Ody via lazarus schrieb am So.,
28. Juli 2024, 13:45:

These are the same, cause in Pascal unlike in C-like languages the end condition of a for-loop is only evaluated once at the start of the loop.

Regards,
Sven

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Matthieu Giroux via lazarus schrieb am So.,
28. Juli 2024, 16:50:

This doesn't change anything regarding efficency except if "list" happens to be some complex expression.

Regards,
Sven

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