Base structure

Program <name>;
Uses <libs>;
Var <vars>: <data_type>;
    <another vars>: <data_type>;

Begin
    <code>
End.

Graphics

Base program

Program <name>;
Uses Graph, <another libs>;
Var gd, gm: Integer;
    <another vars>;

Begin
    DetectGraph(gd, gm);
    InitGraph(gd, gm, '');

    CloseGraph();
End.

Graph commands

Line(x1, y1, x2, y2);
Circle(x, y, r);
Arc(x, y, stAngle, endAngle, radius);
Ellipse(x, y, stAngle, endAngle, xRadius, yRadius);
Rectangle(x1, y1, x2, y2);

General

Syntax

{ <code> } is Begin ... End. or Begin ... End; in pascal
If <condition> Then <command> or Begin <commands> End;

// Switch statement
Case <var> of
    'A': <do-stuff>;
    1..10: <do-stuff>;
Else <command>
End;

For i:= <initial value> To / DownTo <end value (included)> Do <command> or Begin <command> End;
While <condition> Do Begin <code> End;
Repeat <code> Until <condition>;

Procedure <name> (<args_by_copy>; <var args_by_refference>); Var <vars>; Begin <code> End;
Function <name> (<args_by_copy>; <var args_by_refference>) :<return type>; Var <vars>;  Begin <code> End;

// WARNIG!!! - pass by reference vs pass by value
function fun(var x, y: integer);    // the variables are passed by "reference" -> can alter the arguments' values
function fun(x, y: integer);        // the variables are passed by "value" -> can not alter the arguments' values

Comments

// one line comment
{ multi 
  line
  comment }
(* multi line comment
  as well*)

General Procedures and Functions

Write(string s);
WriteLn(string s : int indentation);
Read(any var);
ReadLn(any var);

Crt library

ClrScr; // Clear the screen

Types

byte    // unsigned
shortint
word    // unsigned
integer
longint
int64

array   // <array_name>: array[<from x>..<to y>] of <datatype>

Arrays

var arr: array[1 .. 5] of integer;
var 2dArr: array[1 .. 5, 1 .. 10] of integer    // 2d array with 5 rows and 10 columns

Number functions

div(x)
mod(x)
sqr(x)
sqrt(x)
abs(x)

String functions

str(int, str);
length(s);
val(str, int[, err]);  // err is an index of first character that can not be converted to integer
copy(str, index, count);
delete(str, index, count);
pos(str_to_match, str);
insert(str_to_insert, str, index);

File IO

    // Datatype to represent text file
var: f: text;
     c: char;

    // Bind file to a text variable
    assign(f, 'file.txt');

    // Read only
    // Set cursor to the beginning of the file
    reset(f);
    // Write only
    // Wipes the file and writes to it
    rewrite(f);
    // Write only
    // Writes to the ond of the file
    append(f);
    // Close file
    close(f);

    // Returns true if f is at the end of file
    eof(f);
    // Returns true if f is at the end of line
    eoln(f);

    // Read one character from file
    read(f, c);

Notes

• Functions and Procedures do not accept arrays, you have to manually define a new type of array e.g.: type pole = array[1..20] of integer; and then pass it to a function like: function shiftLeft (arr: pole; size: integer): pole;
• Functions use variables of the same name as their name so function shiftLeft will return like `shiftLeft := ;

Error codes

• 201 - array out of bounds