Object Pascal & Objective-Pascal

Module 2 – Object Pascal & Objective-Pascal — build and test

Page 1 of 3 · About 15 minutes per lesson, including practice.

Collections and repeated work

15-minute session: read for 3 minutes, trace for 3, experiment for 7, and complete the check for 2. Spend longer whenever you need.

A collection stores related values. The loop visits 1, 2, and 3, updating the total from 0 to 1, then 3, then 6. Record this trace rather than guessing. Identify the first and last valid positions in this language: Pascal can declare a 1-based array, while many other examples use zero-based containers. Add another value and update the bounds correctly. Explain what an empty collection should produce.

Object Pascal classes and Objective-Pascal are distinct. First learn class, construction, and Free using the Linux lab. Objective-Pascal adds Objective-C interoperability through mode switches; this lab does not provide that Apple runtime.

program AgilaStudy;
{$mode objfpc}{$H+}{$assertions on}

var Minutes: array[1..3] of Integer; I, Total: Integer;
begin
  Minutes[1] := 1; Minutes[2] := 2; Minutes[3] := 3;
  Total := 0;
  for I := Low(Minutes) to High(Minutes) do Total := Total + Minutes[I];
  writeln(Total);
end.

Expected result: 6

Practice and evidence

Keep three notes: your prediction, the actual result, and why they match or differ. The completion check grades understanding; the practice task builds skill.

Language reference

Example code on Agila Forge ↗