Some doubts in pascal language..

[arthurprs]

Im advancing in pascal but i don't know some things like...

- how use "for in" loops

- a const of arrays

- is there a way to do something like ->
[pascal]var uuu : array [0..1] of integer;
begin
uuu := ((1),(2));[/pascal]

[Parcel]

Im advancing in pascal but i don't know some things like...

- how use "for in" loops

- a const of arrays

- is there a way to do something like ->
[pascal]var uuu : array [0..1] of integer;
begin
uuu := ((1),(2));[/pascal]

[pascal]
const
uuu : array[0..1] of integer = (1,2);
[/pascal]

[JSoftware]

for in can be used to enumerate simple types and userdefined classes alike. Simple types can include chars for strings, elements in a simple array, and something else.. enums or sets I think and a normal TList+TStringlist

For classes you have to override a function called GetEnumerator which should return a class which should inherit some enumerator. Just look at TList's implementation

[arthurprs]

thx for the replys, for in look looks interesting when working with Tlist and other classes

is there a way to do that ?

var
  lol : array [0..1] of Integer;

begin
  lol := (3,2);

[JSoftware]

onme answer.. no

you can't make multiple assignments to arrays in one statement without utilizing hacks

[Mirage]

Why hacks?

type TA = array[0..5] of Integer;

function GetA(const aa: array of Integer): TA;
var i: Integer;
begin
  Assert&#40;High&#40;aa&#41; <= High&#40;TA&#41;, 'Too many parameters'&#41;;
  for i &#58;= 0 to High&#40;aa&#41; do Result&#91;i&#93; &#58;= aa&#91;i&#93;;
end;

var a&#58; TA;

begin
  a &#58;= GetA&#40;&#91;5, 10, 20, 30, 40, 50&#93;&#41;;
end.

This will work even if TA - a dynamic array.

[marcov]

- how use "for in" loops

Well, that is simple: don't.

That is a pretty superficial extension, and the fact that older Delphi's and FPC don't support them is a good reason to avoid it like the plague.

It has one nice application though, iterating over an anonymous set.

[wodzu]

There are some pretty impressive hacks allowing to do this even on Delphi 7.

Check this out

http://andy.jgknet.de/dlang/

[arthurprs]

There are some pretty impressive hacks allowing to do this even on Delphi 7.

Check this out

http://andy.jgknet.de/dlang/

really impresive

[Ramjet]

// Free Pascal
{$assertions on}

procedure stuffints( var a: array of longint; const b: array of longint);
var i: word;
begin
  assert&#40;high&#40;b&#41;<=high&#40;a&#41;, 'Too many args to stuffints.' &#41;;
  for i &#58;= low&#40;b&#41; to high&#40;b&#41; do
    a&#91;i&#93; &#58;= b&#91;i&#93;;
end;

var
  a&#58; array&#91;1..5&#93; of longint;
  ad&#58; array of longint;

begin
  stuffints&#40; a, &#91;11,22,33,44,55&#93; &#41;;
  setlength&#40; ad, 3 &#41;;
  stuffints&#40; ad, &#91;22,33,44&#93; &#41;;
end.