Closures/Value capture: Difference between revisions

=={{header|FreePascal}}==

FreePascal supports the same syntax als Delphi from version 3.3.1.

It needs just a couple of defines.

<syntaxhighlight lang=pascal>

program testthis;

{$mode objfpc}{$modeswitch functionreferences}{$modeswitch anonymousfunctions}

type

TFuncIntResult = reference to function: Integer;

// use function that returns anonymous method to avoid capturing the loop variable

function CreateFunc(i: Integer): TFuncIntResult;

begin

Result :=

function: Integer

begin

Result := i * i;

end;

end;

var

Funcs: array[0..9] of TFuncIntResult;

i: integer;

begin

// create 10 anonymous functions

for i := Low(Funcs) to High(Funcs) do

Funcs[i] := CreateFunc(i);

// call all 10 functions

for i := Low(Funcs) to High(Funcs) do

Writeln(Funcs[i]());

end.</syntaxhighlight>

{{out}}

<pre>

1

4

9

16

25

36

49

64

81

</pre>