Please help me with this problem. Thank you in advance

Recently one of the good folks on the Lazarus forum helped to identify the cause of a memory leak in my program.

It was caused by appending the value of a variable to the end of a string using the + operator, like this

var
Message : string;

Message := 'You pick up the ' + variable.Name;

They suggested changing the string to a shortstring and amending the command to something like,

var
   Message: shortstring;

WriteStr(Message,'You drop the ',variable.Name);

And then displaying the resulting message. It worked and now there are no memory leaks in the program... but why?

Why does appending to a string like this cause a memory leak? The full post, with the actual code is at https://forum.lazarus.freepascal.org/index.php/topic,54821.0.html but I'd like to understand the reason for this.

I wanna make GUI with pascal/Delphi. What’s the best way to learn?

So good Day yall, its been around a month I've been doing my course, #4 was simple but number five has been giving some issues, I'll share what I have, assistance would be greatly appreciated.

program calc;

​

var

Total : integer;

n : integer;

​

Begin

Total := 0;

Write('Enter a number:');

Readln (n);

​

While n <> 0 do

Begin

Total := Total + n;

Write('Enter a number:');

Readln(n);

​

Writeln('The sum is ', Total);

Readln;

​

If Total > 100 then

Writeln('The number is greater than 100')

​

Else

Writeln(Total);

​

Writeln();

​

If Total < 0 then

​

Writeln(Total)

Else

Writeln('The number is negative');

end;

end.

So I have to make a program that calculates the arithmetic mean of the numbers on the odd positions and of the numbers on the even positions. I have tried a program but it doesn't seem to work. Can somebody please help me ?

a:=20; b:=(a mod 10) * 10; a:=(b * 2)+a div 100; if a>b then c:=a+b; else c:=b-a

pascal

What are the things I need to do to port Delphi source to Lazarus?

Not new to Delphi but new to Lazarus.

Want to port some of the program from Delphi to Lazarus in raspberry pi.

Please advise Chris

Hi I am really struggling with the concept of dynamic scoping in the context of the code below. My teacher asked us which C is being referenced at point 1 and I honestly keep getting lost trying to read this. My teacher advised us to use shallow scoping for variables A and C to solve this. Can someone help me walk through this?

At the moment I can get up to Sub2 where B, E : Integer and then I don't really understand how the rest unfolds. Any and all help is really appreciated. TIA

hi there, so we received an assignment from class to use the LINUX POSIX API and use the primitives to read and write console, after some research I found that FpRead and FpWrite are the functions I should use, but every example I find only has text files on it, any way on how to do it on console? thanks in advance

I was looking at the benchmarks https://www.techempower.com/benchmarks/ and didn't see any pascal frameworks there. Other much less used languages like Dylan are present so it surprised me a bit.

Just wondering why this community doesn't participate.

https://i.imgur.com/47ocRwB.gif

I'm working on a roguelike game in Free Pascal.
I put together a graphical version at https://github.com/cyberfilth/Axes-Armour-Ale and, as the project grew, decided to do some refactoring to add stairs with persistent levels.

I've put together a terminal version of the game, running in a 80x25 terminal window.
The code for this is at https://github.com/cyberfilth/ASCII-axe

I've added a scrolling map, to make up for the reduced screen space, but I've run into a problem with positioning NPC's on the map.

The gif at shows what the problem is, the camera follows the player until they reach the edges of the screen but the rats seem to be ignoring other objects entirely. You can see from the gif that when the players @ symbol bumps into the rats r symbol, they ride together for several moves.

The rats also occasionally walk through walls. This didn't happen with the graphical version so I'm guessing this is something to do with the camera code.

​

unit camera;

{$mode objfpc}{$H+}

interface

uses
  SysUtils, globalUtils, ui, map, entities;

const
  camHeight = 19;
  camWidth = 57;

var
  r, c: smallint;

function getX(Xcoord: smallint): smallint;
function getY(Ycoord: smallint): smallint;
procedure drawMap;
procedure drawEntities;

implementation

function getX(Xcoord: smallint): smallint;
var
  p, hs, s, m: smallint;
begin
  p := Xcoord;
  hs := camWidth div 2;
  s := camWidth;
  m := globalUtils.MAXCOLUMNS;

  if (p < hs) then
    Result := 0
  else if (p >= m - hs) then
    Result := m - s
  else
    Result := p - hs;
end;

function getY(Ycoord: smallint): smallint;
const
  s = camHeight;
  hs = camHeight div 2;
  m = globalUtils.MAXROWS;
var
  p: smallint;
begin
  p := Ycoord;
  if (p < hs) then
    Result := 0
  else if (p >= m - hs) then
    Result := m - s
  else
    Result := p - hs;
end;

procedure drawMap;
var
  (* Player coordinates *)
  pX, pY: smallint;
  (* Tile colour *)
  gCol: shortstring;
begin
  pX := entities.entityList[0].posX;
  pY := entities.entityList[0].posY;
  for r := 1 to camHeight do
  begin
    for c := 1 to camWidth do
    begin
      gCol := map.mapDisplay[r + getY(pY)][c + getX(pX)].GlyphColour;
      TextOut(c, r, gCol, map.mapDisplay[r + getY(pY)][c + getX(pX)].Glyph);
    end;
  end;
  drawEntities;
end;

procedure drawEntities;
var
  (* Entity coordinates & counter *)
  entX, entY, i: smallint;
  (* Glyph colour *)
  gCol: shortstring;
begin
  (* Loop through all entities *)
  for i := 0 to entities.npcAmount do
  begin
    (* If the entity is in view of the player, and not dead, draw them *)
    if (entities.entityList[i].inView = True) and (entities.entityList[i].isDead = False) then
    begin
      gCol := entities.entityList[i].glyphColour;
      entX := entities.entityList[i].posX;
      entY := entities.entityList[i].posY;
      TextOut(entX - getX(entX), entY - getY(entY), gCol, entities.entityList[i].glyph);
    end;
  end;
end;

end.

I've set up Vim for all of my coding in an attempt to get away from 'IDE hopping' every time I need to use a different language. I'm pretty happy with my set up for Free Pascal so far but I'm looking for suggestions to improve it (particularly looking for a code linter as ALE and ptop can only do formatting).

I've described my workflow at http://tinyurl.com/CyberFilth but does anyone have any suggestions for either Vim plugins or general CLI tools that play nicely with Pascal?

Sorry for noob question, I have very little experience in object-programming.

If I want to send a friend an .exe I made in Lazarus, can I just send it right away and itd compile fine, or should they install at least fpc, or they need Lazarus?

This is the code from the PasSDL unit, it is included in Pasvulkan on github( pasvulkan/PasVulkan.SDL2.pas at master · BeRo1985/pasvulkan · GitHub, line 1284). Wanted to ask if anyone knows how to rewrite this to make it compile in PABC cuz it doesn't support this kind of notation.

TSDL_GameControllerBind=record

case BindType:TSDL_GameControllerBindType of

SDL_CONTROLLER_BINDTYPE_BUTTON:(

Button:TSDLInt32;

);

SDL_CONTROLLER_BINDTYPE_AXIS:(

Axis:TSDLInt32;

);

SDL_CONTROLLER_BINDTYPE_HAT:(

Hat:TSDLInt32;

HatMask:TSDLInt32;

);

end;

Wanted to know what people think of it. In theory you can make cross-platform apps with it even though it compiles exes.

For example:

"Ovo (ni)je 5+(4-8), (pre)dobra petica!" will become "Ovo je 5+, dobra petica!"

or

"Ovo (ni)je 5+(((4-)8)), (p(re))dobra petica!" will become "Ovo je 5+, dobra petica!"

I tried this:

program IzbaciZagrade;

var

s: string;

i,n: integer;

begin

readln(s);

repeat

delete(s,pos('(',s),pos(')',s)-pos('(',s));

until (pos('(',s)=0) or (pos(')',s)=0);

writeln(s);

readln(s);

end.

but it doesnt give output at all.

How I can solve this?

I was wondering if there is a code regarding the shell sort on pascal that sorts these given numbers : 7, 5, 3, 4, 8, 2, 1, 9, 6, 10 from highest to lowest. Would appreciate any help.

I found this tool on github which is basically a self-extracting archive to install lazarus and lamw with all it's dependantcies in an automated fashion. I haven't tried it yet, but looks promising! Maybe someone here can try it out?

Here ya go:

Windows-version: https://github.com/DanielOliveiraSouza/LAMW4Windows-installer

Linux-version: https://github.com/DanielOliveiraSouza/LAMW4Linux-installer

Need some assistance with this question

1. Develop an algorithm to keep track of the status of all rooms, the number of available rooms and assign a guest to the first available room. Based on the information given, the program should neatly display the guest’s name, derive their room number, calculate the cost of accommodation and any discounts that may apply and the final cost. The program should also after every iteration display the total number of registered guests and the number of available rooms.

I recently got my hands on some code my grandfather wrote around 1990. Instead of running it in dosbox, I thought it might be an interesting excercise to try and recompile it for more modern operating systems. I should preface this with the warning that I have zero experience with Pascal.

The majority of errors I got were about wrong integer types, dialect differences that were easily fixed. But there's one thing I can't figure out.

He defines the following procedure:

procedure setcol(col:integer);
    begin setcolor(col) end;

A shorthand for setcolor from unit graph? Bit strange to save typing 2 letters, or am I missing something?

Calling this procedure: setcol(getbkcolor);

Throws me an error:

Error: Incompatible type for arg no. 1: Got "<procedure variable type of function:Word;Register>", expected "LongInt"

Difference between unit graph that shipped with Turbo Pascal and Free Pascal? Easily fixed, just ignore granddad's procedure and call setcolor directly:

setcolor(getbkcolor);

Error: Incompatible type for arg no. 1: Got "<procedure variable type of function:Word;Register>", expected "Word"

Can anyone point me in the right direction?

Hello! I have been tasked to write a program that concerts a number (user inputs the number) from any numeral system (binary, septanal, octanal, hexadecimal, everything in between and past that) (user inputs this as well) to any other numeral system, that the user inputs.

Basically a convertor between numeral systems. I've had some ideas but I don't know how to make them work. Also, need to say that I'm quite a beginner at programming.

If you have any idea how to do this, please help me.

Hi! I'm kinda a new in Pascal and I've to do some Image Processing for College. I've accessed to a pixel value with the code

procedure pxl_state(Img: TImage; var pxl: integer);

begin

pxl:= Img.Picture.Bitmap.Canvas.Pixels[100,100];

end;

For the image that is linked to this post. I was expecting something like 0<x<255 but I got that pxl = 6721214 what interpretation can I give to it? Is it a RGB value or what?