CSC 155
Computer Science I
Week 1
An Overview of Computers and Programming Languages
Lecture Notes
Student Name
Types of Computer Systems
Here are the classes of computers.
Type
Description
Microcontrollers or Embedded Computers
 The smallest class of computers.
 Are the type of small computer processors that
 are found in small machines and appliances, such
 as a microwave oven, pacemakers, smart cards and
RFIDs.
Microcomputers




Minicomputers
 Are typically larger in size than a microcomputer.
Another name for typical home PC's.
Are manufactured as desktops, as towers or as
laptops.
A Notebook can also be classified as a
Microcomputer, as well as Tablet PCs.
 How about palm pilots?
 Are not as popular as they used to be.
Mainframes
 Are typically used in larger business enterprises.
 Are competitive computer systems with LANs or
 Local Area Networks.
Supercomputers
 Need to be stored in special refrigerated rooms.
 Are used primarily by scientists and engineers to
 perform important computations.
 Dept of Defense, various universities own
supercomputers.
© Copyright 2011 by P.E.P.
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CSC 155
Computer Science I
Week 1
An Overview of Computers and Programming Languages
Lecture Notes
Student Name
What is a Computer Program?
A computer program is a set of instructions which tells a computer to perform
a particular task.
What is an Algorithm?
An algorithm is a step - by - step procedure to solve a problem or to perform
some task.
As an example of a set of instructions, consider the following scenario:
Making popcorn in a microwave oven.
•
•
•
•
•
•
•
•
•
Secure a bag of microwaveable popcorn.
Read the instructions on the popcorn bag.
Place popcorn bag on a dish such that the bag is oriented properly
upward ( this side down )
Place dish with popcorn into microwave oven (open microwave oven
door first )
Next, depress the popcorn button on the microwave ( make sure the
oven’s door is closed )
Wait for popcorn to be properly prepared.
When bell rings, open the oven and carefully grab that hot popcorn
bag.
Commence consumption of contents of the popcorn bag, avoid biting
an any un - popped kernels.
Most likely you will have to share said contents of popcorn bag with a
relative or a friend.
What are the Steps to Program?
(1)
(2)
(3)
(4)
(5)
(6)
Define the Problem
Design a Solution
Develop an Algorithm
Code the Program
Test the Program
Document the Program
What is IPOS?
The IPOS Model is Input, Process, Output and Storage. This is the model that
many programmers use to construct computer programs.
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CSC 155
Computer Science I
Week 1
An Overview of Computers and Programming Languages
Lecture Notes
Student Name
What is Pseudocode?
Not actually a programming language, but English - like statements which are
used to develop an algorithm or a program.
Example of Pseudocode
Pseudocode to find the average of 5 numbers
Set the sum of the values to zero
Set a count of the values to zero
Do as long as the count is less than or equal to 5
Read the next data value
Add this data value to the sum
Add 1 to the count
Divide the sum by 5 to compute the average
Print the average
Example of Pseudocode
Pseudocode to compute employee net pay
Enter the employee’s name
Enter the number of hours worked
Enter the hourly wage
If number of hours worked <= 40 then
gross pay = hours worked * hourly wage
If the number of hours worked > 40 then
gross pay = hours worked * hourly wage
+ 1.5 * ( hours worked – 40 ) * hourly wage
Enter the taxes
net pay = gross pay * taxes
Print the employee’s name and the net pay
What is a Variable?
A variable is a memory location that stores a value or character(s).
How do I Write a Complete Algorithm?
Follow the IPOS to program.
Input - what are the items that the user has to enter into the computer?
Process - what are the expressions that have to be evaluated?
Output - display the end-results to the user
Storage - ensure that the program is available for use at a later time.
© Copyright 2011 by P.E.P.
3
CSC 155
Computer Science I
Week 1
An Overview of Computers and Programming Languages
Lecture Notes
Student Name
Consider this algebraic example:
A circular trampoline measures 62.8 square feet in area. Given   3.14 ,
determine the circumference of the trampoline.
What are the steps to solve this problem?
First, knowing that the area of a circle is
A  r2
We divide the given area A by  .
A /   r 2/
A /  r 2
r 2  A /
Next, take the square root of both sides.
r  ( A / )
Once the radius is known, I can compute the circumference C .
C  2 r
How do I write the above problem using a programming language?
//Here is that math problem written in the C++ language.
//preprocessing directives
#include <iostream>
#include <cmath>
using namespace std;
void main()
{
//First, knowing that the area of a circle is
double A = 62.80, r = 0, C = 0;
//compute the radius r
r = sqrt(A / 3.1416);
//compute the circumference C
C = 2 * 3.1416 * r;
//display the circumference
cout << "the circumference is " << C << endl;
}
Here is the sample output.
© Copyright 2011 by P.E.P.
4
CSC 155
Computer Science I
Week 1
An Overview of Computers and Programming Languages
Lecture Notes
Student Name
What Type Of Programming Applications Can We Create?
(1)
(2)
(3)
(4)
(5)
(6)
Data Structures with functions ( searching and sorting algorithms )
Create RPG ( Role Playing Game ) game simulations.
Examine a binary logarithm.
Examine an infinite series ( sine or cosine ) .
Process data through a file ( linear regression )
Data Encryption ( Cryptography - the Black Chamber )
http://www.simonsingh.net
History of Computer Science Languages
FORTRAN ( 1957 )
COBOL ( 1959 )
BASIC ( 1964 )
C ( 1969 )
C ++ ( 1987 )
Visual Basic ( 1991 )
Java ( 1993 )
C # ( 2001 )
The Future
Science
Business Data Processing
Hobby, Non-Professionals
AT & T
AT & T Object - Oriented
Visual Design Interface
Web Applications ( True OOP language )
A Mixture of Java and C - Web Applications
Natural Languages
A Review of Structured Programming
Textbook Chapter 0
An Introduction to Computers and Programming Languages.
What is a PC System?
http://www.old-computers.com
© Copyright 2011 by P.E.P.
5
CSC 155
Computer Science I
Week 1
An Overview of Computers and Programming Languages
Lecture Notes
Student Name
Type of Languages ( Levels )
Machine ( lowest level )
Assembly
Low - Level
High - Level
Natural Languages ( highest level )
Textbook Chapter 1
Basic Elements of C ++
Declaring Variables and Constants
double Gross_Pay = 0.0;
The above statement declares a variable named Gross_Pay that is initialized
to 0 and is going to hold a real number with decimal points.
int counter = 0;
The above statement declares a variable named counter that is initialized to 0
and is going to hold a real number without decimal points.
Data Types
char
bool
double
int
float
character
Boolean
Real
Integer
Real ( less precision )
Textbook Chapter 2
Input / Output
What are the input and output requirements of a program?
Here are the six steps to writing a good program.
- Define the Problem
- Develop an Algorithm
- Code the Algorithm
- Test the Code
- Implement the Program
- Maintain the Program
© Copyright 2011 by P.E.P.
6
CSC 155
Computer Science I
Week 1
An Overview of Computers and Programming Languages
Lecture Notes
Student Name
Three Types of Program Control
- Sequence ( in a step by step order )
- Selection ( making a decision )
- Repetition ( looping )
An example of sequence control: determining the total purchase price
after a number of items have been selected for purchase
Using Visual Studio 2010
MS Web Site Visual C++ Express Edition 2010
http://www.microsoft.com/express
Review Questions
(1)
The language of a computer program is the same as the __________ .
(a)
(c)
(2)
logical design
flowchart
wisdom into data
information into data
input
an assignment statement
(b)
(d)
output
input and output
!
(b)
@
(c)
#
(d)
+
(e)
&
Which is true about variables?
(a)
(b)
(c)
(d)
(e)
(6)
wisdom into knowledge
data into information
In computer programming, the symbol to sum two numbers is __________ .
(a)
(5)
(b)
(d)
A parallelogram in a flowchart represents __________ .
(a)
(c)
(4)
syntax
philosophical orientation
An information system will transform __________ .
(a)
(c)
(3)
(b)
(d)
The underscore is the only symbol that can be used in a variable name.
The name must be on the keyword list.
The name is created by the compiler.
The name is generated by the Java design environment.
The name must start with a capital letter.
Which mathematical operation is performed first in an equation with no parentheses?
(a)
(c)
Addition
Exponentiation
© Copyright 2011 by P.E.P.
(b)
(d)
Division
Integer division
7
CSC 155
Computer Science I
Week 1
An Overview of Computers and Programming Languages
Lecture Notes
Student Name
(7)
Which is true about an assignment statement?
(a)
(b)
(c)
(d)
(e)
(8)
Printing a document is a type of __________ .
(a)
(c)
(9)
assignment
output
(b)
(d)
input
assignment and input
Which data type uses double quotation marks?
(a)
(c)
(10)
They store user key strokes.
They store user mouse clicks.
They put the results of an operation in a variable.
They display information at a prompt.
They display strings in a message box.
string
decimal
(b)
(d)
character
integer
Pseudocode is __________ .
(a)
(b)
(c)
(d)
(e)
data that have been encoded for security
the incorrect results of a computer program
a program that does not work
the obscure language computer personnel use when speaking
a description of an algorithm similar to a computer language
Input, Process and Output - Programming Exercises
Enter the correct answer(s) in the space(s) provided.
(11)
Identify the following flowchart symbol and describe its use.
This is a parallelogram symbol that is used for
both input and output statements.
(12)
Identify the following flowchart symbol and describe its use.
This is a diamond symbol that is used for a
decision statement.
(13)
In computer programming, a variable is a symbol or name that stands for a value. For
example, in the expression 2 * x + y , x and y are variables.
What are the variables in the following expression?
p , r and t
p + p * r * t / 100
(14)
An orbiting satellite traveled 3,500 miles in 45 minutes. What variable names would you
use to find the satellite’s speed in miles per hour?
miles, minutes, milesPerHour
© Copyright 2011 by P.E.P.
8
CSC 155
Computer Science I
Week 1
An Overview of Computers and Programming Languages
Lecture Notes
Student Name
(15)
Complete the following chart by entering either Integer, Decimal or String as the data
type which bests matches the given variable name.
variable name
interest_Earnings
numberOfUnits
employeeName
volume_Cylinder
DollarAmountInAccount
(16)
data type
Decimal
Integer
String
Decimal
Decimal
Name three things that can be done in the housekeeping section of a program.
(1) declare programmer name(s), (2) declare variable names and (3) add
comment statements.
(17)
A program that is free of syntax errors is free of logical errors. (a) True (b) False
Removing syntax errors is independent of freeing a program of logic errors.
(18)
Logical errors are much easier to locate than syntax errors.
(a) True (b) False
Logic errors are often more difficult to locate compared to syntax errors.
(19)
Often the programmer does not design the output.
(a) True (b) False
Programs are generally designed around the output.
(20)
Although a flowchart ( as its name suggests ) depicts data flow very well, it is not easily
modified once written.
(a)
True
(b)
False
Sample Online Quiz
(1)
You have been assigned to write a program that finds the batting
averages for members of a local baseball team. What should be your
first step in the process of solving this problem?
(a)
(b)
(c)
(d)
(2)
Which step occurs first in the execution of a C ++ program?
(a)
(c)
(3)
Determine who will be using the program
( This is part of defining the problem in the Top - Down
approach. )
Determine the program inputs
Determine the program outputs
Write and test valid pseudocode
execution
loading
(b)
(d)
linking
preprocessing
Which of these is a legal identifier in C ++ ?
(a)
(c)
PIE * 2
2_DAY
© Copyright 2011 by P.E.P.
(b)
(d)
gross Pay
NUM_1
9
CSC 155
Computer Science I
Week 1
An Overview of Computers and Programming Languages
Lecture Notes
Student Name
(4)
Suppose a , b and c are int variables and a = 5 and b = 6 . What
is the value of a after this statement executes:
a = (b++) + 3;
(a)
(c)
(5)
5
10
(b)
(d)
9
11
Suppose a, b, and c are int variables and a=5 and b=6. What is the
value of a after this statement executes:
a = (++b) + 3;
(a)
(c)
(6)
iostream
io.h
cmath
stdlib.h
object - oriented
structured
modular
All of the above
C ++ enables __________ programming.
(a)
(b)
(c)
(d)
(9)
9
11
C ++ enables __________ programming.
(a)
(b)
(c)
(d)
(8)
(b)
(d)
To use the predefined identifiers cin and cout in your C ++
program, make sure to include the < __________ > header file.
(a)
(b)
(c)
(d)
(7)
8
10
operative
object - oriented
structured
structured and object-oriented
The ___________ translates code written in a high - level language
into machine language.
(a)
(b)
(c)
(d)
assembler
compiler
preprocessor
linker
© Copyright 2011 by P.E.P.
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