Programming Concepts

OUTPUTPROCESSINPUT

Computer Fundamentals

TERMINOLOGIES:

Program - A set of instructions, written in a specific programming language, which a computer follows in processing data, performing an operation, or solving a logical problem.

Software – Programs

Hardware - Physical component of a computer

DATA vs. INFORMATION

DATA – a collection of facts relating to events that take place. These facts could be in the form of numbers, letters, special symbols or combination of these.

INFORMATION – data that has been organized and processed so that it is meaningful. It is essential for effective performance of management functions of planning, organizing, directing, and controlling for effective internal operations and external reporting.

DATA PROCESSING CYCLE

The process of converting data into useful and meaningful information:

THE PROGRAMMING CYCLE

1.) Defining the Problem2.) Developing Software Requirements3.) Designing the Program4.) Coding the Program5.) Checking out the program by Testing and Debugging6.) Installing and Maintaining the Program7.) Documentation

Program Elements and Structure 1.) Constants – Literal Value that does not change during program execution. It can be of the numeric or string type. Numeric Constant - may be an integer (whole number) or a real number (with a decimal place). It may be preceded by a positive or negative sign. Examples:

10 -28 +3.4 -0.413 0 201

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Note: No other characters must or can appear together with the constants. The following are examples of incorrect numeric constants:

10,000 $14.3 10mi/hr 1/2 String Constant – A character or group of characters enclosed in double quotation marks ( “ ). The numbers 0-9, letters a-z or A-Z and all special characters like a space, % $ - _ & etc. may be included. Examples:

“C” “Tina” “.” “1225” “B & L” Note: The entire string constant must always be enclosed in double quotation marks, one before the first character and one after the last character (no more no less). The following are examples of incorrect string constants: “Cristina A. Pascua ACT” “Power Plant

2.) Variables – Is a portion of the computer’s main memory used to store a numeric or string constant. The value stored in the variable must be given a unique variable name but it can only hold one value at a given time. Variable names must conform to the following requirements:

a.) Must contain only letters, numbers and/or an underscore.b.) Must begin with a letter.c.) Must Stop either with a letter or a number.d.) Must be unique that is, not a name of another variable.e.) Must not be a keyword like IF, WHILE and the like.

Note: Variable names are case sensitive, that is, upper and lower case letters are differentiated. For example the variable TOTAL is not the same as total. The following are example of incorrect variable name:

Year code 10ctr #5 Total=

3.) Expressions – is a group of program elements consisting of operands and operators. Operands can be a constant, variable, and or an array element. Operators can be arithmetic, logical, relational and/or string. Expressions always yield a value of a certain type depending on the type of expressions used.

Arithmetic Expressions

Hierarchy or Priority of Operators

1.) Expressions in parenthesis2.) * / %3.) + -

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Examples: 1.) 10 + 4 * 8

= 10 + 32 = 42

2.) 50 % 6 – 5= 2 – 5= -3

3.) 20 / 4 * 9

= 5 * 9= 45

String Expressions Examples:

1.) “3” + “4” = “34”2.) “Cris” + “tina” = ”Cristina”

Examples of incorrect usage of the + operator:

“3” + 4 100 + “Peso”

Relational Expressions

Greater than > Less than or equal to <=Less than < Not equal !=Greater than or equal to >= Is equal to ==

Examples:

Ctr1 > 10 3 <= 5 Temp1 != Temp2 Examples of incorrect Relational Expressions:

30 <= X <= 40 43 > < 50

Logical Expressions

Hierarchy or Priority of Operators

1.) Expressions in parenthesis2.) Not (!)3.) And (&&)4.) Or (||)

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TRUTH TABLE FOR NOT(!)

X !XFALSE TRUETRUE FALSE

TRUTH TABLE FOR AND(&&)

X Y X && YFALSE FALSE FALSEFALSE TRUE FALSETRUE FALSE FALSETRUE TRUE TRUE

TRUTH TABLE FOR OR(||)

X Y X || YFALSE FALSE FALSEFALSE TRUE TRUETRUE FALSE TRUETRUE TRUE TRUE

Examples:

15 >= 10 && 15 <= 20 T && T T

Statements – are keywords, which perform a predefined procedure. The following statements are available:

1.) IF Statement2.) WHILE Statement3.) FOR Statement

Exercises:

1.) 11 % 2 + 3 * 7 –22.) 100 % 5 % 3 % 23.) – (45 / 9) * 6 + 44.) (5 + 7) % (10 * 2 – 5) / (15 – (8 – 6 % 4))5.) (8 + 21 % (18 – 5 * 3)) % (17 – (6 + 13 % 5))6.) (12 == 12 % 2 * 2) && !(( 5 > 3) && (8<3))7.) (6 > 3) && (8 != 8) || !(10 <= 10)8.) 15 / 3 == 15 % 39.) 5 != 11 / 2

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Exercises:

10.) Number of enrollees exceeded 5,000 students.11.) HEIGHT is at least 170 cm.12.) REVENUE is at most 80% of SALES.13.) X is either 6, 8 , or 1014.) X is any number except 1, 2, and 3.15.) X is between 100 and 200.

FLOWCHARTS

- A graphic form of an algorithm.- A diagram of a sequence of steps that a program must perform to produce the desired output.- Traditional tool of programmers which allow flexibility in terms of detail to be included.

TYPES OF FLOWCHARTS

1.) System Flowchart – present the total picture without worrying about taking care of every detail.2.) Program Flowcharts – depicts a main segment of a complete computer program.

FLOWCHARTING GUIDELINES

1.) Always use the ANSI standard symbols.2.) Construct your flowcharts to read from top to bottom and left to right.3.) Do not crisscross flow lines (used labeled connectors and use arrowheads to indicate direction of the flow.4.) Make the messages and labels in the flowchart symbol direct and descriptive.5.) Strive for neatness, clarity and simplicity.

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Terminal Symbol

Decision Symbol

Preparation Symbol

Processing Symbol

Offpage Connector

Predefined Process Symbol

Onpage Connector

Flow Direction Lines


BASIC FLOWCHARTING SYMBOLS

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Input/Output Symbol

Punched Card

Document Printout

Magnetic Tape

Online Storage


PSEUDOCODE

- An outline of a program.- There is no real formatting or syntax rules for pseudocode.- It cannot be compiled nor executed.

A SIMPLE PSEUDOCODE

This pseudocode will prompt the user to input length and width of a rectangle and compute and output its area

start Declarations num length num width num area output “Input length and width of a rectangle: “ input length input width

area = length * width output “Area of a rectangle = “, areastop

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C++ SPECIFICS

Data Types

Type Size Range of Values

unsigned short int 2 bytes 0 to 65, 535short int 2 bytes -32,768 to 32,767unsigned long int 4 bytes 0 to 4, 294,967,295long int 4 bytes -2,147,483,648 to 2,147,483,647int 4 bytes -2,147,483,648 to 2,147,483,647unsigned int 4 bytes 0 to 4, 294,967,295char 1 bytes 256 charactersbool 1 bytes true or falsefloat 4 bytes 1.2e-38 to3.4e38double 8 bytes 2.2e-308 to 1.8e308

Escape Sequence Character

Character combinations consisting of a backslash (\) followed by a letter or by a

combination of digit is called "escape sequences."

Escape Sequence Represents

\a Bell (alert)\b Backspace\f Formfeed\n New line\r Carriage return\t Horizontal tab\v Vertical tab\' Single quotation mark\ " Double quotation mark\\ Backslash\? Literal question mark

\ ooo ASCII character in octal notation\x hh ASCII character in hexadecimal notation

\x hhhh Unicode character in hexadecimal notation if this escape sequence is used in a wide-character constant or a Unicode string literal. For example, WCHAR f = L'\x4e00' or WCHAR b[] = L"The Chinese character for one is \x4e00".

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C++ SPECIFICS

Compound Operators

In addition to basic Arithmetic operators, compound operators are available in C++.

The following are the compound Operators in C++: *=, /=, %=, +=, and - =

Normal Arithmetic Expression Arithmetic Expression Using Compound

Operators

Var = Var * 2 Var *= 2

Var = Var / 3 Var /= 3

Var = Var % 5 Var %= 5

Var = Var + 4 Var += 4

Var = Var – 1 Var -= 1

Unary Operators (Prefix and Postfix)

The available unary operators in C++ are ++ which increments a variable by 1 and - -

which decrements a variable by 1. It can be written as PREFIX or before the variable or

POSTFIX after the variable.

PREFIX Example: ++X or - - X

POSTFIX Example: X++ or X - -

Sample Program 1 :

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#include<iostream.h>int main(){ int num1=1, num2=2;

num1++; cout<<num1++<<endl;

++num2; cout<<num2++<<endl<<endl;

}

Value of num1 = 2 and value of num2 = 3

/*This program will prompt the user to input length and width of a rectangle and compute and output its area*/

//Programmer: CRISTINA A. PASCUA

#include<iostream.h>

int main(){ int length, width, area;

cout<<“Input length and width of a rectangle: “; cin>>length>>width; area = length * width;

cout<<“ Area of a rectangle = “<<area;

return 0;}

1

2

34

5

7

9

8

6


Sample Program 2 :

A SIMPLE C++ PROGRAM

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#include<iostream.h>int main(){ int num1=1, num2=2;

++num1; cout<<++num1<<endl;

num2++; cout<<++num2<<endl<<endl;

}

Value of num1 = 3 and value of num2 = 4


ELEMENTS OF A C++ PROGRAM

1.) comment – represented by // for a single line comment and /* */ for multiple line comments.

2.) compiler directives 3.) main function4.) variables5.) data types

data types includes the following: int, float, double, char6.) special characters

; - terminates a statement, - separates variable names of the same type() – used in function declaration and function call{ } – begin and end symbol

7.) expressions – can be arithmetic, relational and logical8.) reserved word – cannot be used as a user defined identifier.

example: return, int, float, double, char, for, while, do, etc.9.) statements - any line terminated by a semicolon

Basic input statement used in C++ is cin

syntax: cin>>variable_name; cin>>var1>>var2>>var3;

example: cin>>num; cin>>num1>>num2>>num3;

Basic output statement used in C++ is cout

syntax: cout<<variable_name; cout<<var1<<var2<<var3; cout<<“string”; cout<<“string”<<variable_name;

example: cout<<num; cout<<num1<<num2<<num3; cout<<“Hello Philippines Mabuhay!”; cout<<“Sum = “<<sum;

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Flowchart

Start

F = 0

Input C

F = (9.0/5.0) * C + 32

Output F

Stop

C++ Program

#include <iostream >using namespace std;

int main(){ double F, C;

F = 0; cout<<” Input temperature in Celsius: ”; cin>> C; F = (9.0 / 5.0) * C + 32; cout<< “Temperature in Fahrenheit:”<<F<<endl; return 0;}


SEQUENTIAL PROGRAM STRUCTURE

1.) Create a flowchart and a C++ program that will input temperature in Celsius and output the corresponding temperature in Fahrenheit.

The formula is a follows:

Fahrenheit = 9 (Celsius) + 32 5

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Declarationsnum F, C

Flowchart

Start

TBill = 0change = 0

Input GBill, Amt

TBill = Gbill + Gbill *0.1 + Gbill * 0.05change = Amt - TBill

Stop

C++ Program

#include<iostream>using namespace std;

int main(){ int GBill, Amt, change, TBill;TBill = 0; change = 0; cout<< ” Input Gross Bill and Amount Given: ”; cin>> GBill>> Amt;TBill = GBill + GBill * 0.1 + GBill * 0.05;change = Amt – Tbill; cout<< “Total Bill = ”<< Tbill<<endl; cout<< “Change = ”<< change<<endl; return 0;}

Declarations num GBill, Amt, change, TBill


2.) Pepperoni++ Pizza House charges 10% service charge and 5% sales tax on the gross bill of the customer. Create a flowchart and a C++ program that would input the gross bill of the customer and the amount given by the customer to the waiter. It must output the customer’s total bill and change (if there’s any).

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Output TBill, change

Flowchart

Start

AC = 0

Input DO

Output AC

Stop

AC = (1000.00 * DO) / (10-DO)

Declarations num DO, AC


3.) Ten young men agreed to purchase a gift worth 10,000 Pesos for their super idol. In addition, they agreed to continue with their plan even if at least one of them drops out. Create a flowchart and a C++ program that would input the number of men who dropped out (assume 0 to 9 only) and output how much more will each have to contribute toward the purchase of the gift.

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C++ Program

#include <iostream>using namespace std;

int main(){ double DO, AC;

AC = 0; cout<< ” Input number of men who dropped out: ”; cin>> DO; AC = (1000.00 * DO) / (10 – DO); cout “Additional Contribution =”<< AC<<endl; return 0;}

Flowchart

Start

RDigit = 0

Input number

RDigit = number % 10

Output RDigit

Stop

C++ Program

#include<iostream>using namespace std;

int main(){ int num, RDigit;RDigit = 0; cout<< ” Input an integer number: ”; cin>> num; RDigit = num % 10; cout<< “It’s rightmost digit is ”<<RDigit<<endl; return 0;}

Declarations num number, RDigit


4.) Create a flowchart and a C++ program that would input an integer number and then output its one’s digit or the right most digit.

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Flowchart

Start

Retro = 0NS = 0

Input OS

Retro = (OS *0.155) *2NS = OS + OS * 0.155

Output Retro, NS

Stop

C++ Program


int main(){ double OS, Retro, NS;

Retro = 0;NS = 0; cout<<” Input employees old salary: ”; cin>>OS; Retro = (OS * 0.155) * 2; NS = OS + OS * 0.155; cout<<“Retroactive pay = ”<<Retro<<endl; cout<<“New salary = ”<<NS<<endl; return 0;}

Declarations num OS, Retro, NS


5.) Workers at a particular company were given a 15.5% salary increase. Moreover, the increase was retroactive for 2 months, that is, effective two months ago. Create a flowchart and a C++ program that takes the employee’s old salary as input and then output the amount of retroactive pay (balance) due the employee and his new salary as well.

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Flowchart

Start

Temp = 0

Input A, B, C, D

Temp = AA = DD = CC = B

B = Temp

Output A, B, C, D

Stop

C++ Program


int main() { int A, B, C, D, Temp;

cout<< ” Input values for A, B, C, and D: ”; cin>> A>> B>> C>> D; Temp = A;A = D;D = C;C = B;B = Temp; cout<< A<<endl<< B<<endl<< C<<endl<< D<<endl; return 0;}

Declarations num A, B, C, D, Temp


6.) Create a flowchart and a C++ program that would input numeric values to A, B, C, D and exchange their values such that A goes to B, B goes to C, C goes to D, and D goes to A.

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Programming Concepts

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