Programming on Algorithmic Languages

1.1 General Notes About C++ and This Course
Course geared toward novice programmers
Stress programming clarity
C and C++ are portable languages
Portability
C and C++ programs can run on many different computers
Compatibility
Many features of current versions of C++ not compatible with older implementations

1.1 General Notes About C++ and This Course
What do you need?
Books:
C++ How to Program, Fifth (fourth) Edition By H. M. Deitel - Deitel & Associates
C++A Beginner’s Guide By Herbert Schildt
Absolute C++ By Walter Savitch
IDE:
Microsoft Visual C++ 2008 (Express or Professional editions)
Sites:
http://cplusplus.com/
http://e-practice.org
http://www.iitu.kz/
Your Mind (Brain)

1.2 Introduction to C++ Programming
C++ language
Facilitates structured and disciplined approach to computer program design
Following several examples
Illustrate many important features of C++
Each analyzed one statement at a time
Structured programming
Object-oriented programming

1.3 Basics of a Typical C++ Environment
C++ systems
Program-development environment
Language
C++ Standard Library

1.3 Basics of a Typical C++ Environment
Phases of C++ Programs:
Edit
Preprocess
Compile
Link
Load
Execute

1.3 Basics of a Typical C++ Environment
Input/output
cin
Standard input stream
Normally keyboard
cout
Standard output stream
Normally computer screen
cerr
Standard error stream
Display error messages

1.3 A Simple Program:
Printing a Line of Text
Comments
Document programs
Improve program readability
Ignored by compiler
Single-line comment
Begin with //
Preprocessor directives
Processed by preprocessor before compiling
Begin with #

1 // Fig. 1.2: fig01_02.cpp
2 // A first program in C++.
3 #include
4
5 // function main begins program execution
6 int main()
7 {
8 std::cout << "Welcome to C++!\n";
9
10 return 0; // indicate that program ended successfully
11
12 } // end function main
Welcome to C++!

1.31 A Simple Program:
Printing a Line of Text
Standard output stream object
std::cout
“Connected” to screen
<<
Stream insertion operator
Value to right (right operand) inserted into output stream
Namespace
std:: specifies using name that belongs to “namespace” std
std:: removed through use of using statements
Escape characters
\
Indicates “special” character output

1.31 A Simple Program:
Printing a Line of Text

1 // Fig. 1.4: fig01_04.cpp
2 // Printing a line with multiple statements.
3 #include
4
5 // function main begins program execution
6 int main()
7 {
8 std::cout << "Welcome ";
9 std::cout << "to C++!\n";
10
11 return 0; // indicate that program ended successfully
12
13 } // end function main
Welcome to C++!

1 // Fig. 1.5: fig01_05.cpp
2 // Printing multiple lines with a single statement
3 #include
4
5 // function main begins program execution
6 int main()
7 {
8 std::cout << "Welcome\nto\n\nC++!\n";
9
10 return 0; // indicate that program ended successfully
11
12 } // end function main
Welcome
to
C++!

1.4 Variables
Variables
Location in memory where value can be stored
Common data types
int - integer numbers
char - characters
double - floating point numbers
Declare variables with name and data type before use
int integer1;
int integer2;
int sum;
Can declare several variables of same type in one declaration
Comma-separated list
int integer1, integer2, sum;

Variables
Variable names
Valid identifier
Series of characters (letters, digits, underscores)
Cannot begin with digit
Case sensitive
1.4 Variables

1.5 Memory Concepts
Variable names
Correspond to actual locations in computer's memory
Every variable has name, type, size and value
When new value placed into variable, overwrites previous value
Reading variables from memory nondestructive

1.5 Memory Concepts
std::cin >> integer1;
Assume user entered 45
std::cin >> integer2;
Assume user entered 72
sum = integer1 + integer2;

1.6 Data types
C and C++ have four basic built-in data types, described here for binary-based machines.
char is for character storage and uses a minimum of 8 bits (one byte) of storage, although it may be larger.
int stores an integral number and uses a minimum of two bytes of storage.
The float and double types store floating-point numbers, usually in IEEE floating-point format. float is for single precision floating point and double is for double-precision floating point.

1.6 Data types

1.6 Data types
Specifiers
Specifiers modify the meanings of the basic built-in types and expand them to a much larger set. There are four specifiers:
Long
Short
Signed
Unsigned

1.6 Data types
The exact sizes and ranges of values for the fundamental types are implementation dependent.
The range of values a type supports depends on the number of bytes that are used to represent that type.
Consider a system with 4 byte (32 bits) ints.
signed int type, the nonnegative values are in the range 0 to 2,147,483,647 (231 1).
signed int type, the negative values are in the range 1 to 2,147,483,648 (231).
unsigned int on the same system would use the same number of bits to represent data, but would not represent any negative values.

1.6 C++ Data Types
The guaranteed
minimum range for
each type as
specified by the
ANSI/ISO C++
standard

1. C++ Data Types

1.7 Arithmetic
Arithmetic calculations
*
Multiplication
/
Division
Integer division truncates remainder
7 / 5 evaluates to 1
%
Modulus operator returns remainder
7 % 5 evaluates to 2

1.7 Arithmetic
Rules of operator precedence
Operators in parentheses evaluated first
Nested/embedded parentheses
Operators in innermost pair first
Multiplication, division, modulus applied next
Operators applied from left to right
Addition, subtraction applied last
Operators applied from left to right

1.7 Arithmetic

1.8 Decision Making: Equality and Relational Operators
if structure
Make decision based on truth or falsity of condition
If condition met, body executed
Else, body not executed
Equality and relational operators
Equality operators
Same level of precedence
Relational operators
Same level of precedence
Associate left to right

1.8 Decision Making: Equality and Relational Operators

1 //
2 // Using if statements, relational
3 // operators, and equality operators.
4 #include
5
6 using std::cout; // program uses cout
7 using std::cin; // program uses cin
8 using std::endl; // program uses endl
9
10 // function main begins program execution
11 int main()
12 {
13 int num1; // first number to be read from user
14 int num2; // second number to be read from user
15
16 cout << "Enter two integers, and I will tell you\n"
17 << "the relationships they satisfy: ";
18 cin >> num1 >> num2; // read two integers
19
20 if ( num1 == num2 )
21 cout << num1 << " is equal to " << num2 << endl;
22
23 if ( num1 != num2 )
24 cout << num1 << " is not equal to " << num2 << endl;
25

26 if ( num1 < num2 )
27 cout << num1 << " is less than " << num2 << endl;
28
29 if ( num1 > num2 )
30 cout << num1 << " is greater than " << num2 << endl;
31
32 if ( num1 <= num2 )
33 cout << num1 << " is less than or equal to "
34 << num2 << endl;
35
36 if ( num1 >= num2 )
37 cout << num1 << " is greater than or equal to "
38 << num2 << endl;
39
40 return 0; // indicate that program ended successfully
41
42 } // end function main

Enter two integers, and I will tell you
the relationships they satisfy: 7 7
7 is equal to 7
7 is less than or equal to 7
7 is greater than or equal to 7
Enter two integers, and I will tell you
the relationships they satisfy: 22 12
22 is not equal to 12
22 is greater than 12
22 is greater than or equal to 12

Readings:
C++ How to Program, By H. M. Deitel
Chapter 1. Introduction to Computers, the Internet and World Wide Web
Chapter 2. Introduction to C++ Programming