I want Integer, NOT the longint! (with Lazarus 0.9.28.2)
lazarus / 11-Options

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xaero · 2010-05-23 01:49

Code: [Select]programe test;
var a:integer;
begin
    a:=40000;
    writeln(pred(a));
end.
In Lazarus,this will output 39999!!!
but actually "a" is an integer, can't take 40000！
how to Correct it？？？

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Ocye · 2010-05-23 02:33

An integer has no predefined size. FPC uses 32bit or 16bit
(http://lazarus-ccr.sourceforge.net/docs/rtl/objpas/integer.html). If
you want to ensure 16bit signed respectively a range from -32,768 to
+32,767 use "smallint".

http://en.wikipedia.org/wiki/Integer_%28computer_science%29

One punctuation mark is enough.

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marcov · 2010-05-23 06:23

Quote from: xaero on May 23, 2010, 03:49:33 amCode: [Select]programe
test;
var a:integer;
begin
    a:=40000;
    writeln(pred(a));
end.
In Lazarus,this will output 39999!!!
but actually "a" is an integer, can't take 40000！

Check your settings and compiler mode, and make sure it is a TP-like
mode (TP or FPC), and not a delphi like mode that has integer=32-bit.
(objfpc, delphi)

I tested your code and prints

[Turtle] </home/marcov/testing> ./test
-25537

if compiled with the proper mode,

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xaero · 2010-05-23 20:49

Thanks !

and how to make FPC mode as the default setting?

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Leledumbo · 2010-05-24 00:02

Quoteand how to make FPC mode as the default setting?It's in compiler
options.

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stonefull · 2010-05-24 09:35

Change mode on:

{$mode fpc}{$H+}

Code: [Select]program inteiro;

{$mode fpc}{$H+}  // change mode here

uses
  {$IFDEF UNIX}{$IFDEF UseCThreads}
  cthreads,
  {$ENDIF}{$ENDIF}
  Classes
  { you can add units after this };
var
  a: integer;
{$R *.res}

begin
  a := 40000;
  writeln(pred(a));
  readln;
end.

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marcov · 2010-05-24 14:43

FPC mode is the default, without $mode directives or -Sd/-S2 etc
cmdline parameters

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xaero · 2010-05-24 19:10

Many thanks !

But in my Lazarus(v0.9.28.2), Object Pascal(-Mobjfpc) is the default!

with Project --> Complier Option menu , I can set FPC(-Mfpc) as the
current project's complier mode
but when I create another new project, it automaticly changes to the
default complier(-Mobjfpc)!!!!

how to change the complier mode of  every project i create to
FPC(-Mfpc)? (I don't like write the code "{$mode fpc}" etc in every
project)

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mas steindorff · 2010-05-24 21:16

just so you know, you are going about this integer resizing all
wrong.  the define of an integer is to be system and OS dependant.  it
should change with the upcoming 64 bit OS.  it would be best to define
a variable to be the size you wish like this

Type
  S8 = ShortInt;
  U8 = byte;
  chr8 = ANSIChar;  // or char
  S16 = SmallInt;
  U16 = word;
  S32 = LongInt;
  U32 = Cardinal;
  F32 = single;
  F64 = Double;

Then you only have one place to change if any of the types get
promoted. this type define can be inside some os dependant ifdefs as
well for more portability

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skalogryz · 2010-05-25 00:07

Quote from: xaero on May 24, 2010, 09:10:35 pmhow to change the
complier mode of  every project i create to FPC(-Mfpc)? (I don't like
write the code "{$mode fpc}" etc in every project)
It's not supported for now to select "a default mode".

But you don't need to write {$mode fpc} in every unit or project. Just
change the  Project -> Complier Options -> Syntax Mode option on each
project created. The mode would be used for all compiled units
(without explicit {$mode xxx} setting).

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marcov · 2010-05-25 04:02

Quote from: mas steindorff on May 24, 2010, 11:16:16 pm  it should
change with the upcoming 64 bit OS. 

(no it doesn't)

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xaero · 2010-05-25 06:13

thanks, Moderator
thanks everyone

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genomega · 2010-06-05 14:51

Found this answer searching, thanks.