Defining a function

function Square(x: integer): integer;
begin
  Square := x * x;
end;

begin
  writeln(Square(5));
end.

A function's name is declared with its parameter and return types; inside the body, assigning to the function's own name (Square := ...) is how it returns a value.

Procedures

A procedure is like a function but returns nothing:

procedure Greet(name: string);
begin
  writeln('Hello, ', name, '!');
end;

begin
  Greet('Ada');
end.

Arrays

An array is a fixed-size, ordered collection -- its size is part of its declared type:

var
  fruits: array[0..2] of string;
begin
  fruits[0] := 'apple';
  fruits[1] := 'banana';
  fruits[2] := 'cherry';
  writeln(fruits[0]);      { apple -- indexing starts at 0 }
  writeln(length(fruits)); { 3 }
end.

Looping over an array

var
  i: integer;
begin
  for i := 0 to length(fruits) - 1 do
    writeln(fruits[i]);
end.

Why This Matters for Your Exams

Unlike a Python list, a Pascal array's size is fixed at declaration -- there's no .append(). Reaching for an index past the declared bound is a runtime error, not a silent resize, so always declare arrays large enough for what you'll store in them.

Try it yourself