1. Module 1: Introduction to Programming
Comparison between low-level and high-level languages /History and Development of C and C Differences between C and C++ - Advantages of C++- Algorithm - Pseudo code
Introduction to Programming Languages

2. Objectives Upon completion of this module, you will be able to:
Define what is computer programming
Define terms related to computer programming such as source code, programs, etc.
Know the difference between an Assembly Language and Machine Language
Describe what are the low and high-level languages
Know the difference between procedural and object-oriented programming

3. Objectives Know the history of C++ Compare C++ from C
Know the advantages of using C++
Explain the Program Development Cycle
Define what is an algorithm
Know how to express algorithms using pseudo code, flowcharts, and programming languages

4. Computer Program
A computer program (also a software program, or just a program) is a sequence of instructions written to perform a specified task for a computer.  A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute the instructions.

5. Source Code
Source code is text written in a computer programming language. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source code, which can then be automatically translated to binary machine code that the computer can directly read and execute.

6. Computer Programming
Computer programming (often shortened to programming or coding) is the process of designing, writing, testing, debugging/ troubleshooting, and maintaining the source code of computer programs. This source code is written in a programming language. The purpose of programming is to create a program that exhibits a certain desired behavior. The process of writing source code often requires expertise in many different subjects, including knowledge of the application domain, specialized algorithms and formal logic.

7. Introduction to Programming
Program: self-contained set of instructions used to operate a computer to produce a specific result
Also called software
Programming: the process of writing a program, or software

8. Machine Language
Machine language programs, also called executables, consist of binary instructions
Each instruction has two parts:
Instruction part: the operation to be performed; also called an opcode
Address part: memory address of the data to be used
Each class of computer has its own particular machine language
Writing in machine language is tedious!

9. Assembly Languages
Assembly Language: programming language with symbolic names for opcodes, and decimals or labels for memory addresses
Example:
ADD 1, 2
MUL 2, 3
Assembly language programs must be translated into machine instructions, using an assembler

10. Introduction to Programming: Assembly Language (continued)

11. Introduction to Programming:
Low-level languages: languages that use instructions tied directly to one type of computer
Examples: machine language, assembly language
High-level languages: instructions resemble written languages, such as English,and can be run on a variety of computer types
Examples: Visual Basic, C, C++, Java

12. Introduction to Programming: (continued)
Source code: the programs written in a high- or low-level language
Source code must be translated to machine instructions in one of two ways:
Interpreter: each statement is translated individually and executed immediately after translation
Compiler: all statements are translated and stored as an executable program, or object program; execution occurs later

13. Low- and High-Level Languages (continued)
Large C++ programs may be stored in two or more separate program files due to
Use of previously written code
Use of code provided by the compiler
Modular design of the program (for reusability of components)
Linker: combines all of the compiled code required for the program

14. Low- and High-Level Languages (continued)
Programs can also be classified by their orientation:
Procedural: available instructions are used to create self-contained units called procedures
Object-oriented: reusable objects, containing code and data, are manipulated
Object-oriented languages support reusing existing code more easily

15. Procedural and Object Orientations
Figure 1.2 Creating an executable C++ program.

16. History of C++
During the 60s
ALGOL 60, was developed as an alternative to FORTRAN taking from it some concepts of structured programming which would later inspire most procedural languages.
ALGOL 68 also directly influenced the development of data types in C. Nevertheless ALGOL was an non-specific language and its abstraction made it impractical to solve most commercial tasks.

17. History of C++ (continued)
In 1963 the CPL (Combined Programming language) appeared with the idea of being more specific for concrete programming tasks of that time than ALGOL or FORTRAN. Nevertheless this same specificity made it a big language and, therefore, difficult to learn and implement.

18. History of C++ (continued)
In 1967, Martin Richards developed the BCPL (Basic Combined Programming Language), that signified a simplification of CPL but kept most important features the language offered. Although it too was an abstract and somewhat large language.

19. History of C++ (continued)
In 1970, Ken Thompson, immersed in the development of UNIX at Bell Labs, created the B language. It was a port of BCPL for a specific machine and system (DEC PDP-7 and UNIX), and was adapted to his particular taste and necessities. The final result was an even greater simplification of CPL, although dependent on the system. It had great limitations, like it did not compile to executable code but threaded-code, which generates slower code in execution, and therefore was inadequate for the development of an operating system.

20. History of C++ (continued)
Therefore, from 1971, Dennis Ritchie, from the Bell Labs team, began the development of a B compiler which, among other things, was able to generate executable code directly. This "New B", finally called C, introduced in addition, some other new concepts to the language like data types (char).

21. History of C++ (continued)
The C programming language was designed by Dennies Ritchie in 1973 at Bell Laboratories. It was first used system implementation language for the nascent Unix operating system. The main reason to devised C was to overcome the limitations of B.  It was Derived from the type-less language BCPL (Basic Combined Programming Language). C was was the evolution of B and BCPL by incorporating type checking. It was originally intended for use in writing compilers for other languages.

22. History of C++ (continued)
Dennis Ritchie (September 9, 1941 – October 12, 2011) was an American computer scientist and winner, with Kenneth Thompson, of the 1983 Turing Award. He created the C programming language and, with Thompson, the Unix operating system, which have had pervasive and lasting influence on subsequent programming languages and operating systems.

23. History of C++ (continued)
In 1980, Bjarne Stroustrup, from Bell labs, began the development of the C++ language, that would receive formally this name at the end of 1983, when its first manual was going to be published. In October 1985, the first commercial release of the language appeared as well as the first edition of the book "The C++ Programming Language" by Bjarne Stroustrup.
In the words of Bjarne Stroustrup "the name signifies the evolutionary nature of the changes from C".  That is during when C++ was evolving initially, it was called as new C or C with classes. The "+" is actually the operator's sign used in programming languages normally for coding purposes.

24. History of C++ (continued)
Bjarne Stroustrup (born December 30, 1950) is a computer scientist and creator of the C++programming language.
Professor and holder of the College of Engineering Chair in Computer Science

25. History of C++ (continued)
During the 80s, the C++ language was being refined until it became a language with its own personality. All that with very few losses of compatibility with the code with C, and without resigning to its most important characteristics. In fact, the ANSI standard for the C language published in 1989 took good part of the contributions of C++ to structured programming. From 1990 on, ANSI committee X3J16 began the development of a specific standard for C++. In the period elapsed until the publication of the standard in 1998, C++ lived a great expansion in its use and today is the preferred language to develop professional applications on all platforms. C++ has been evolving, and a new version of the standard, c++0x, is being developed to be published soon, with several new features.

26. Difference of C and C++
C++ is an extension of C language. This means that you can not only use the new features introduced with C++ but can also use the power and efficiency of C language. C and C++ are no more language for writing compilers and other languages, these general purpose languages are used worldwide in every field. 
However, C++ does not retain complete source-level compatibility with C.

27. C++ allows expression of abstract ideas
Advantages of C++
C++ allows expression of abstract ideas
C++ still allows a programmer to keep low-level control
C++ has national standards (*ANSI)
C++ is reusable and object-oriented
C++ is widely used and taught
1. C++ allows expression of abstract ideas
C++ is a third generation language that allows a programmer to express their ideas at a high level as compared to assembly languages.
2. C++ still allows a programmer to keep low-level control
Even though C++ is a third generation language, it has some of the "feel" of an assembly language. It allows a programmmer to get down into the low-level workings and tune as necessary. C++ allows programmers strict control over memory management.
3. C++ has national standards (ANSI)
C++ is a language with national standards. This is good for many reasons. Code written in C++ that conforms to the national standards can be easily integrated with preexisting code. Also, this allows programmers to reuse certain common libraries, so certain common functions do not need to be written more than once, and these functions behave the same anywhere they are used.
4. C++ is reusable and object-oriented
C++ is an object-oriented language. This makes programming conceptually easier (once the object paradigm has been learned) and allows easy reuse of code, or parts of code through inheritance.
5. C++ is widely used and taught
C++ is a very widely used programming language. Because of this, there are many tools available for C++ programming, and there is a broad base of programmers contributing to the C++ "community".
*ANSI: American National Standard Institute

28. Here is a list of differences between C and C++:
The main difference between C and C++ is that C++ is object oriented while C is function or procedure oriented.
C++ has a much larger library
You must declare functions before use. Although most good C code will follow this convention, in C++ it is strictly enforced that all functions must be declared before they are used.

29. Difference of C and C++
In C, main() doesn't provide return 0 automatically. In C++, you are free to leave off the statement 'return 0;' at the end of main; it will be provided automatically:
int main()
{ printf( "Hello, World" ); }
but in C, you must manually add it:
int main()
{ printf( "Hello, World" );
return 0; }

30. The Development of C++
The purpose of most application programs is to process data to produce specific results
Figure 1.3 Basic procedural operations.

31. The Development of C++ (continued)
Early procedural languages included
FORTRAN: Formula Translation
ALGOL: Algorithmic Language
COBOL: Common Business Oriented Language
BASIC: Beginners All-purpose Symbolic Instruction Code
Pascal C

32. The Development of C++ (continued)
Early object-oriented language:
C++

33. Program Development Cycle
1. Analyze: Define the problem
2. Design: Plan the solution to the problem
3. Choose the Interface: Select the objects
4. Code: Translate the algorithm into a programming language.
5. Debug and Test: Locate and remove any errors in the program.
6. Complete the Documentation: Organize all the materials that describe the program.

34. Algorithms
Algorithm: the step-by-step sequence of instructions that describe how the data is to be processed to produce the desired output
Programming = the translation of the selected algorithm into a language the computer can use

35. Algorithms (continued)
Pseudocode: English-like phrases used to describe the algorithm
Formula: description of a mathematical equation
Flowchart: diagram showing the flow of instructions in an algorithm
Flowcharts use special symbols

36. Expressing Algorithms
Algorithms can be expressed in many kinds of notation, including: 
Natural Languages
Pseudocode
Flowcharts
Programming Languages

37. Pseudocode A program design technique that uses English words.
Has no formal syntactical rules.
Pseudo means false, thus pseudocode means false code. It looks like (imitates) real code but it is NOT real code.
Pseudocode cannot be compiled nor executed, and there are no real formatting or syntax rules.
Pseudocode should not include keywords in any specific computer languages.
The benefit of pseudocode is that it enables the programmer to concentrate on the algorithms without worrying about all the syntactic details of a particular programming language.

38. How do I write Pseudocode?
First you may want to make a list of the main tasks that must
be accomplished on a piece of scratch paper.
Then, focus on each of those tasks. Generally, you should try
to break each main task down into very small tasks that can
each be explained with a short phrase.
There may eventually be a one-to-one correlation between
the lines of pseudocode and the lines of the code that you
write after you have finished pseudocoding.

39. Some Keywords That Should be Used
It is not necessary in pseudocode to mention the need to
declare variables. It is wise however to show the initialization
of variables.
All statements showing "dependency" are to be indented.
These include while, do, for, if, switch.
Some Keywords That Should be Used
For looping and selection, the keywords that are to be used include:
Do While...EndDo Call ... with (parameters)
Do Until...Enddo Call
Case...EndCase Return
If...Endif When

40. As verbs, use the words:
Generate, Compute, Process
Set, Reset, Increment, Compute, Test
Calculate, Add, Sum, Multiply, ...
Print, Display, Input, Output, Edit

41. Pseudocode Examples Original Program Specification:
Write a program that obtains two integer numbers from the user. It will print out the sum of those numbers.
Pseudocode:
Prompt the user to enter the first integer Prompt the user to enter a second integer Compute the sum of the two user inputs Display an output prompt that explains the answer as the sum Display the result

42. Original Program Specification: 
Write a program that will display if the entered student’s grade is passed of failed. Passing grade is 70.
Pseudocode:
Prompt the user to enter a student grade
If student's grade is greater than or equal to 70
Print "passed"
else
Print "failed"

43. Original Program Specification: 
Write a program that will allow the student to input the grade on his 5 subjects and will compute for his average grade.
Set total to zero
Set grade counter to one
While grade counter is less than or equal to 5
Input the next grade
Add the grade into the total
Set the class average to the total divided by 5
Print the class average.

44. Pseudocode example :  If then Else
If age > 17
Display a message indicating you can vote.
Else
Display a message indicating you can't vote.
Endif
Pseudocode example : Case
Case of age
0 to 17 Display "You can't vote."
18 to 64 Display "Your in your working years."
Display "You should be retired."
Endcase

45. Pseudocode example : While loop
count assigned zero
While count < 5
Display "I love computers!"
Increment count
Endwhile
Pseudocode example : For loop
For x starts at 0, x < 5, increment x
Display "Are we having fun?"
Endfor

46. Pseudocode example : Do While loop
count assigned five Do
Display "Blast off is soon!"
Decrement count
While count > zero
Pseudocode example : Repeat Until loop
Repeat
Until count < one

47. Pseudocode example : Function with no parameter passing
Function clear monitor
Pass In: nothing
Direct the operating system to clear the monitor Pass Out: nothing
Endfunction
Pseudocode example : Function with parameter passing
Function delay program so you can see the monitor
Pass In: integer representing tenths of a second Using the operating system delay the program
Pass Out: nothing
Endfunction

48. Pseudocode of : Function main calling the clear monitor function
Pass In: nothing
Doing some lines of code
Call: clear monitor
Pass Out: value zero to the operating system Endfunction

49. Flowcharts Symbols

50. Flowcharts Symbols (continued)

51. Flowcharts (continued)
Flowchart for calculating the average of three numbers.

52. Guidelines for Drawing a Flowchart
In drawing a proper flowchart, all necessary requirements
should be listed out in logical order.
The flowchart should be clear, neat and easy to follow. There
should not be any room for ambiguity in understanding the
flowchart.
The usual direction of the flow of a procedure or system is
from left to right or top to bottom.

53. Only one flow line should come out from a process symbol.
Only one flow line should enter a decision symbol, but two or
three flow lines, one for each possible answer, should leave the
decision symbol.

54. If the flowchart becomes complex, it is better to use
connector symbols to reduce the number of flow lines.
Avoid the intersection of flow lines if you want to make it
more effective and better way of communication.
Ensure that the flowchart has a logical start and finish.
It is useful to test the validity of the flowchart by passing
through it with a simple test data.

55. Advantages of using flowcharts
The benefits of flowcharts are as follows:
Communication: Flowcharts are better way of communicating
the logic of a system to all concerned.
Effective analysis: With the help of flowchart, problem can be
analyzed in more effective way.
Proper documentation: Program flowcharts serve as a good
program documentation, which is needed for various purposes.

56. Efficient Coding: The flowcharts act as a guide or blueprint during the systems analysis and program development phase.
Proper Debugging: The flowchart helps in debugging process.
Efficient Program Maintenance: The maintenance of operating
program becomes easy with the help of flowchart. It helps the
programmer to put efforts more efficiently on that part

57. Limitations of using flowcharts
Complex logic: Sometimes, the program logic is quite
complicated. In that case, flowchart becomes complex and
clumsy.
Alterations and Modifications: If alterations are required the
flowchart may require re-drawing completely.
Reproduction: As the flowchart symbols cannot be typed,
reproduction of flowchart becomes a problem.

58. Flowcharting Examples
Draw a flowchart to find the sum of first 50 natural numbers.

59. Example 2
Draw a flowchart to find the largest of three numbers A,B, and C.

60. Example 3
Draw a flowchart for computing factorial N (N!)
Where N! = 1 ´ 2 ´ 3 ´ …… N .

61. Problem Solving Process
Input
Process
Output

62. Input Process Output Example Problem #1
Calculate and display the price of a number of apples if the quantity in kg and price per kg are given.
Input
Process
Output
Quantity
Price_per_kg
Price = Quantity * Price_per_kg
Price

63. Pseudocode
Start
Read quantity
Read price_per_kg
price  quantity * price_per_kg
Print price
End

64. Price = Quantity * Price_per_kg
Flowchart: Calculate Price of Apples
Input
Quantity
Start
Price = Quantity * Price_per_kg
Price_per_kg
Output
Price
End

65. Source Code Pre-processor Main function Start Variable declarations
#include<iostream>
using namespace std;
int main() {
int price = 0, quantity = 0;
float price_per_kg = 0;
cout << "Enter quantity of an apple : " ;
cin >> quantity;
cout << "Enter price of an apple per kilogram : " ;
cin >> price_per_kg;
price = quantity * price_per_kg;
cout << "The price of an apple in kilogram is " << price << "\n";
system ("pause");
return 0; }
Pre-processor
Main function
Start
Variable declarations
Input
computations
#include <iostream>
Output
Stop

66. ???? Process Example #2 A car park has the following charges:
The 1st hour costs Php The subsequent hour cost Php 2.00 per hour. Write an algorithm based on a vehicle’s entry and exit time.
Entry_time
Exit_time
Charge
????
Input
Process
Output

67. Period = Exit_time – Entry_time
Flowchart: Calculate Car Park Charge
Start
Input Entry_time
Input Exit_time
Period = Exit_time – Entry_time If
Period > 1
Charge = 5
Charge = (Period -1) * 2
Yes No
Output
Charge
End

68. C++ Program: Calculate Car Park Charge
#include<iostream>
using namespace std;
int main() {
int entry_time = 0, exit_time = 0, period = 0;
float charge = 0;
cout << "Enter entry time : " ;
cin >> entry_time;
cout << "Enter exit time : " ;
cin >> exit_time;
period = exit_time – entry_time;
If (period > 1)
charge = (period – 1)* 2;
else
charge = 5;
cout << “The total parking charge is “ << charge << “\n”;
system ("pause");
return 0; }

69. Laboratory
Activities

70. Problem #1:
Create a flowchart together with program that computes the fare of a taxi passenger. The 1st four kilometers is Php and the succeeding kilometer is Php

71. Problem #2:
Create a flowchart that add, subtract, multiply, and divide two numbers.

72. End of Module 1