Programming

Every problem can be broken into three parts that describe how raw data becomes a useful result.

📚 IPO Examples

🛠️ Activity 1 — IPO Classifier

For each item below click to classify it as Input, Process, or Output for: "Finding the average of 5 exam marks." Click an item multiple times to cycle through categories.

An algorithm is a step-by-step procedure for solving a problem. Three control structures direct the flow.

IF condition THEN
  statement when True
ELSE
  statement when False
ENDIF

🛠️ Activity 2 — Identify the Control Structure

Flowcharts use standard symbols to visually represent an algorithm step by step.

🔷 Flowchart Symbols

📊 Flowchart Examples

🛠️ Activity 3 — Flowchart Symbol Quiz

Pseudo code expresses an algorithm in simple English-like terms, independent of any programming language.

🔑 Keywords

📄 Pseudo Code Examples

BEGIN
  INPUT Radius
  CALCULATE Area = 22/7 × Radius × Radius
  DISPLAY Area
END

BEGIN
  READ number as N
  CALCULATE Rem = N MOD 2
  IF Rem = 0 THEN
    DISPLAY "Even number"
  ELSE
    DISPLAY "Odd number"
  ENDIF
END

BEGIN
  Total = 0 ; n = 1
  WHILE n <= 10
    READ Number
    Total = Total + Number
    n = n + 1
  ENDWHILE
  DISPLAY Total
END

BEGIN
  Total = 0 ; count = 0
  REPEAT
    READ Number
    Total = Total + Number
    count = count + 1
  UNTIL count = 10
  Average = Total / 10
  DISPLAY Total, Average
END

BEGIN
  INPUT N
  Min = N ; Count = 1
  WHILE Count < 10
    INPUT N
    IF N < Min THEN
      Min = N
    ENDIF
    Count = Count + 1
  ENDWHILE
  DISPLAY Min
END

Pascal is a high-level, structured programming language ideal for learning fundamental programming concepts.

🏷️ Identifiers

📦 Data Types

⚡ Operators

🛠️ Activity 4 — Expression Evaluator

📄 Basic Pascal Program

program addNum(input,output);         { Program name }
var
  num1, num2, total : integer;    { Declare variables }
  avg                : real;
begin                                  { Main program starts }
  Writeln('Enter First Number');
  Read(num1);                         { Input }
  Writeln('Enter Second Number');
  Read(num2);
  total := num1 + num2;               { Process }
  avg   := total / 2;
  Writeln('Total = ', total);          { Output }
  Writeln('Average = ', avg);
end.                                   { Main program ends }

Pascal provides IF-THEN, IF-THEN-ELSE, Nested IF, and CASE statements for selection.

if N > 0 then
  Writeln('Positive Number');

Read(N1, N2);
if N1 > N2 then
  Large := N1
else
  Large := N2;
Writeln('Large = ', Large);

Read(M);
if M >= 75 then  Grade := 'A'
else if M >= 65 then  Grade := 'B'
else if M >= 50 then  Grade := 'C'
else if M >= 35 then  Grade := 'S'
else                   Grade := 'F';

Read(Marks);
case Marks of
   0..34  : Grade := 'W';
  35..49  : Grade := 'S';
  50..64  : Grade := 'C';
  65..74  : Grade := 'B';
  75..100 : Grade := 'A';
  else Writeln('Invalid');
end;

🛠️ Activity 5 — Grade Calculator

Three loop structures handle different repetition scenarios in Pascal programs.

var i, total : integer;
begin
  total := 0;
  for i := 1 to 10 do
  begin
    Writeln(i);
    total := total + i;
  end;
  Writeln('Total = ', total);
end.

for count := 10 downto 1 do
  Writeln(count);

n := 5;
while n <= 50 do
begin
  Writeln(n);
  n := n + 5;
end;

count := 0;
repeat
  Writeln('Pascal');
  count := count + 1;
until count > 5;

🛠️ Activity 6 — Loop Trace Simulator

Arrays store multiple same-type values. Sub-programs (Procedures & Functions) organize code into reusable blocks.

📦 Arrays

{ General syntax }
var Name : array[first..last] of type;

{ Example: 10 integers, index 0–9 }
var marks : array[0..9] of integer;

{ Assign values }
marks[0] := 45;
marks[1] := 75;

{ Loop through all elements }
for i := 0 to 9 do
  Writeln(marks[i]);

🔧 Sub-Programs

procedure showArea(var r:real);
begin
  Writeln(22/7 * r * r);
end;
{ Call: } showArea(radius);

function square(var n:integer):integer;
begin
  square := n * n;
end;
{ Call: } res := square(5); { res=25 }

Programming languages evolved from complex machine code to human-friendly high-level languages.

⚙️ Translators

🧩 Programming Paradigms

12 questions covering all topics. Click an answer to check immediately.

Exam-style questions with detailed answers. Try each one before revealing the solution.

BEGIN
  INPUT Year
  IF (Year MOD 400 = 0) THEN
    DISPLAY "Leap Year"
  ELSE IF (Year MOD 100 = 0) THEN
    DISPLAY "Not a Leap Year"
  ELSE IF (Year MOD 4 = 0) THEN
    DISPLAY "Leap Year"
  ELSE
    DISPLAY "Not a Leap Year"
  ENDIF
END

program positives(input,output);
var i, num : integer;
begin
  for i := 1 to 10 do
  begin
    Write('Enter number ',i,': '); Read(num);
    if num > 0 then
      Writeln(num, ' is positive');
  end;
end.

program findMax(input,output);
var
  marks : array[0..4] of integer;
  i, max : integer;
begin
  for i := 0 to 4 do
  begin
    Write('Marks ',i+1,': '); Read(marks[i]);
  end;
  max := marks[0];
  for i := 1 to 4 do
    if marks[i] > max then max := marks[i];
  Writeln('Highest mark = ', max);
end.

program rectangle(input,output);
var L, W : real;

procedure calcRect(var len, wid : real);
var area, perim : real;
begin
  area  := len * wid;
  perim := 2 * (len + wid);
  Writeln('Area = ', area);
  Writeln('Perimeter = ', perim);
end;

begin
  Write('Length: '); Read(L);
  Write('Width: ');  Read(W);
  calcRect(L, W);
end.