Computer Programming
Chapter (7)
Computer Programming
Computer Programming
Objectives
Program and Programming
Algorithms & Programs
Computer Programming Languages
Flowchart
Examples
Program and Programming
Program: مجموعة من األوامر المكتوبة بلغة برمجة يقوم الحاسب بتنفيذها
• A set of instruction written in a programming language that a
computer can execute so that the machine acts in a
predetermined way.
• Program solves a problem البرنامج يحل مشكلة معينة
• Before writing a program:
– Have a thorough understanding of the problem
– Carefully plan an approach for solving it.
Programming: البرمجة هي عملية كتابة أوامر للحاسب تخبر المعالج بما يجب أن
يقوم به
• The Process of providing instructions to the computer that tells
the processor what to do.
Algorithms and Programs
الخوارزمي يقدم حال لمشكلة دون االعتماد على أي لغة للبرمجة بينما
البرنامج عبارة عن خوارزمي مكتوب بلغة معينة
• An Algorithm is a solution to a problem that is
independent of any programming language.
While
• A program is an algorithm expressed using a
specific set of instructions from any
programming language.
Algorithm Example
• Maximum of two numbers
Steps:
1.Read/input two numbers
2.Compare two numbers
3.Print the Greater number
• Average of three numbers
Steps:
1.Read/input three numbers
2.Add three numbers
3. divide the sum by 3.
4.Print the result of division
Computer Languages
- Machine language
- Assembly languages
- High-level languages
6
Machine Language
• Programs and memory locations are written
in strings of 0s and 1s.
• Problems with machine languages
– Programs are difficult to write and debug
• Only option available to early programmers.
7
Assembly Language
– For example, A for add, C for compare, etc.
– Use names rather than binary addresses for
memory locations
• Require an assembler to translate the program
into machine language.
8
High-Level Languages
• Transformed programming
– Programs could be written and debugged
much more quickly
• Requires a compiler to convert the
statements into machine language
– Each computer has its own version of a
compiler for each language.
9
Major Programming Languages
• FORTRAN
• COBOL
• BASIC
• Visual Basic
• C/C++
• Java
10
Flowcharts
Flowcharts
Flowchart
Flowchart
– It is a graphical representation of an algorithm.
– Components:
• Arrows/lines: Flow of control
• Parallelogram: Indicates input and output operations
• Rectangle symbol (action symbol): Indicates any type of
action/computational step
• Oval symbol: Indicates the start or the end of a program or a
section of code.
• Diamond: Decision.
12
Flowcharts
Flowchart Notations
Arrows
Diamond
Parallelogram
Oval
Rectangle
13
Flowcharts
Examples
Flowcharts
Example: Add Two Numbers
START
READ
A,B
Sum = A+B
PRINT
Sum
Stop
15
Flowcharts
Example: Average of Three Numbers
START
READ
A,B,C
Sum= A+B+C
Average = (A+B+C) / 3
Avg = Sum / 3
PRINT
Average
Stop
16
Flowcharts
Example: Area of a Circle
START
READ
R
Area = 3.14 * R * R
PRINT
Area
Stop
17
Flowcharts
Decision Making (Selection)
Flowcharts
Example: Max. of Two Numbers
START
READ
N1, N2
PRINT Yes No PRINT
N1 If N1>N2
N2
Stop
19
Flowcharts
Example: Pass or Fail
START
READ
D
PRINT Yes No PRINT
“Pass” If D>=60
“Fail”
Stop
20
Flowcharts
Example: Degree to Grade
START
READ
D
PRINT Yes No No No No PRINT
If D>=90 If D>=80 If D>=70 If D>=60 “F”
“A”
Yes Yes Yes
PRINT PRINT PRINT
“B” “C” “D”
Stop
21
