This document provides an overview of Pascal programming including: - The basics of algorithms, flowcharts, and pseudocode for representing problems - An introduction to the Pascal programming language, its history, popularity, and the Turbo Pascal integrated development environment - Key Pascal concepts like identifiers, reserved words, data types, variables, constants, and control structures - Examples of Pascal programs for calculating sums, checking conditions, and using selection and repetition structures - How to work with arrays, functions, and procedures as fundamental programming structures in Pascal The document contains explanations, syntax examples, and exercises to help learn and practice Pascal programming.

1. Write programs to solve problems
Pascal Programming
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By Anutthara Senanayake
Lecturer
Sri Lanka International Buddhist Academy

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Session 01
A problem
Input, Output and Process
Alternative solutions
Algorithm
Control Structures in Algorithms
To display Algorithms : Flowcharts & Pseudocodes
Pascal Programming
Why Pascal is more popular ?
Turbo Pascal
Identifiers
Reserved Words
Data Types
Variables
Constants
Program Structure
Control Structures
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A Problem
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Problem 01
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Input , Output & Process
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Algorithms
Definition
An algorithm is a
procedure or
formula for solving
a problem.
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Control Structures in Algorithms
Sequence
Selection
Iteration
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To display Algorithms : Flowcharts &
Pseudocodes
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Pascal Programming
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Pascal is a general-purpose, high-level
language that was originally developed by
Niklaus Wirth in the early 1970s.
It was developed for teaching programming
as a systematic discipline and to develop
reliable and efficient programs.

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Why Pascal is more popular ?
Easy to learn.
Structured language.
It produces transparent, efficient and reliable programs.
It can be compiled on a variety of computer platforms.
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Turbo Pascal
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Additional Notes
How to run turbo Pascal in Dos Box - Type following commands
Mount c C:TP
C:
Cd BIN
turbo.exe
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Identifiers
Identifiers are names that allow you to reference stored
values, such as variables and constants.
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Exercise 01
Select the valid identifiers from the given list.
1. Myname
2. @me2
3. me2
4. saman
5. my-add
6. my_add
7. $sea_u 14

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Reserved Words
program, input, output, var, real, begin, readline, writeline , end
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Data Types
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Variables
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var myname : string

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Constants
A const is a keyword
applied to a data type
that indicates that the
data is constant (does
not vary).
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Const pi=22/7;

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Operators
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Arithmetic Operators
Relational Operators
Logical Operators

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Program Structure
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Program Name
Library
Main program starting
point
Main program ending
point
Output

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Exercise 02
Write a Pascal program to calculate the sum of two integer
numbers.
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Control Structures - IF…THEN…ENDIF
Exercise 03
Write a Pascal program to print the entered, number if it is
only a positive number.
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Exercise 04
Write a Pascal program to print “Pass” if the mark is greater
than 50.
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Control Structures - IF….THEN….ELSE…..ENDIF
Exercise 05
Write a Pascal program to find the maximum number out of
two given numbers.
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Control Structures -Nested IF
Exercise 07
Write a Pascal program to print the correct grade for the
given mark. (mark >= 75 =>A, mark >=65=> B, mark >=50 =>C,
mark =>35=>S, else F)
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Exercise 08
Write a Pascal program to display the day of the week when
the day number is provided.
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Control Structures - CASE statements
Exercise 09
Write a Pascal program to print the grade according to the
criteria for the given mark.
0-34 => F , 35 – 49 =>S , 50 – 64 =>C, 65 – 74 => B, 75 – 100
=>A
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Control Structures - FOR - DO
Exercise 10
Write a Pascal program to print numbers starting from 10 to
1.
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Exercise 11
Write a Pascal program to calculate the sum and the average
of given 10 numbers.
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Control Structures -WHILE DO
Exercise 12
Develop a computer based solution to receive a set of
positive numbers or 0 from user and display the total value.
Data input will stop when a negative value is entered.
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Control Structures - REPEAT UNTIL
Exercise 13
Write a Pascal program to print the word “Pascal” 5 times.
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Control Structures - Nested Control Structures
Exercise 14
Write a Pascal program to make a number series according
to the ascending or descending order
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Exercise 15
Write a Pascal program to input numbers and calculate the
count of odd numbers and the count of even numbers.
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Lets do some more on Pascal
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Session 02
Arrays
Declaring Arrays
Assigning Values
Accessing Values
Sub Programs
Functions
Defining a Function
Function Declarations
Calling a Functions
Procedures
Defining a Procedure
Procedure Declarations
Calling a Procedure
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Arrays
An array is a highly useful
data structure that stores
variable data having
the same data type
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An array is said to be a static data structure because, once declared, its original
size that is specified by the programmer will remain the same throughout the
whole program and cannot be changed.

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Declaring Arrays
Syntax
Var
<arrayName> : Array[n..m] of <Data Type>;
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Assigning Values
Syntax
<arrayName>[index] := <relevant data>
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Accessing Values
By using a for loop we can easily access the array
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Exercise 01
Write a Pascal program to find the sum of a given integer array.
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Sub Programs
• A subprogram is a program unit/module that performs a particular task.
• These subprograms are combined to form larger programs.
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Pascal provides two kinds of subprograms:
Functions: these subprograms return a single value.
Procedures: these subprograms do not return a value
directly.
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Functions
A function is a group of statements that together perform a task.
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Function Declarations
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Calling a Functions

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Procedures
Procedures are subprograms that, instead of returning a single value,
allow to obtain a group of results.
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Procedure Declarations
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Calling a Procedure

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53. Thank you !
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