Basic of Programming (Introduction to Programming)

Basic Programming Concepts Imran Rashid
Basic Programming Concepts
Imran Rashid
CTO at ManiWeber Technologies

Outline
Program, Programming & Programming Languages
Variables, Constants & Data Types
Operators in Programming
Decision Making in Programming
Iterations in Programming

Program
A computer program, or just a program, is a sequence of
instructions, written to perform a specified task on a
computer
Programming
Computer programming is the process of writing or
editing source code
A person who practices this skill is referred to as a
computer programmer, software developer, and
sometimes coder
Programming Languages
A programming language is a formal constructed language
designed to communicate instructions to a machine

Type of Programming Languages

Language Translation Process (High to Low)

Type of Language Translators

Compiler v.s Interpreter

Type of Errors in Programming

Variables & Constants
Most important concept for problem solving using
computers
All temporary results are stored in terms of variables
oThe value of a variable can be changed
oThe value of a constant do not change
Where are they stored?
In main memory
How does memory look like (logically)?
As a list of storage locations, each having a unique address
Variables and constants are stored in these storages

Data Types
Three common data types used:
oInteger: can store only whole numbers
– Examples: 25, -56, 1, 0
– Size: 16 bits & 32 bits
oFloating-point: can store numbers with fractional values
– Examples: 3.14159, 5.0, -12345.345
oCharacter: can store a character
– Examples: ‘A’, ‘a’, ‘*’, ‘3’, ‘ ’, ‘+’

Arithmetic Operators
Addition (+)
Subtraction (-)
Division (/)
Multiplication (*)
Modulus (%)
Examples
distance = rate * time;
netIncome = income - tax;
speed = distance / time;
area = PI * radius * radius;

Suppose x and y are two integer variables, whose values
are 13 and 5 respectively

Operator Precedence
In decreasing order of priority
oParentheses: ( )
oUnary minus: –5
oMultiplication, Division, and Modulus
oAddition and Subtraction
For operators of the same priority, evaluation is from left
to right as they appear
Parenthesis may be used to change the precedence of
operator evaluation

Relational Operators
Used to compare two quantities

Logical Operators
There are two logical operators (also called logical
connectives)
o&& : Logical AND
– Result is true if both the operands are true
o|| : Logical OR
– Result is true if at least one of the operands are true

Statements and Blocks
An expression followed by a semicolon becomes a
statement
ox = 5;
oy = x + 3;
Braces { and } are used to group declarations and
statements together into a compound statement, or block

Control Statements: What do they do?
Allow different sets of instructions to be executed
depending on the outcome of a logical test
oWhether TRUE (non-zero) or FALSE (zero)
How do we specify the conditions?
Using relational operators (<, <=, >, >=, ==, !=)
Using logical operators (&&, ||, !)

The if Statement
The condition to be tested is any expression enclosed in
parentheses
The expression is evaluated, and if its value is non-zero,
the statement is executed

The if-else Statement
These statements can be nested

The switch Statement
This causes a particular group of statements to be chosen
from several available groups
oUses “switch” statement and “case” labels

Loop
Group of instructions that are executed repeatedly while
some condition remains true
Loops can be nested as well
There are 3 main types of loops
owhile loop
odo-while loop
ofor loop

while loop
The while loop is used to carry out looping operations, in
which a group of statements is executed repeatedly, as
long as some condition remains satisfied

do-while loop
A do while loop is a control flow statement that executes a
block of code at least once, and then repeatedly executes
the block, or not, depending on a given boolean condition
at the end of the block

for loop
The for loop is the most commonly used looping structure
in programming for known iterations
oexpr1 (init) : initialize parameters
oexpr2 (test): test condition, loop continues if satisfied
oexpr3 (update): used to alter the value of the parameters
after each iteration

LAB
Total Marks: [2 + 2 + 2 + 2 + 2 = 10]
Q: In GIMS there are 500 students, 12 class rooms, 2 labs, 4 departments,
20 admin staff, 32 teachers, 6 degree programs (e.g. BSCS/BSIT), & 3
busses.
1. Store this information in proper data types, variable/constant names &
values (use proper naming conventions)?
2. Every teacher starts his/her lecture at certain time & it has an end time
(which programming construct is applied in this scenario & how)?
3. A teacher can arrange extra/makeup classes only of the room & class is
free (which programming construct is applied in this scenario & how)?
4. Bus 1, 2 & 3 has fixed root (e.g. bus 1 move students from Kharian to
Gujrat) (which programming construct is applied in this scenario &
how)?
5. A teacher might be a permanent one or visiting
(which programming construct is applied in this scenario & how)?

ASSIGNMENT
Submission Date 22/10/2018 & in written form [10]
Q1 (a): Do some R&D on the internet and write down the
syntaxes of the following things:
1. How to declare a variable
2. How to declare a constant
3. How to make a decision with if-else-if & switch
4. How to make an unknown and known iteration (for &
while/do-while)
Q1 (b): Do the above mention activities in the following
languages:
1. C++
2. PHP
3. JavaScript
4. C#

Basic of Programming (Introduction to Programming)

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