MELJUN CORTES--IT102 Introduction to C Programming Complete

8/8/2019 MELJUN CORTES--IT102 Introduction to C Programming Complete

1/47

Introduction To C++ ProgrammingLanguage

by: MELJUN P. CORTES,MBA,MPA

LECTURE 3


2/47

What is C++

C++ is a high-levellanguage and it is evolved

from C over a period of several years starting

in 1980. The standard for C++ was jointly developed

by the American National Standards Institute(ANSI) and the International Standards

Organization (ISO).

a set of rules, symbols, and special words usedto construct a computer program.


3/47

Structure of a C++ Program

Figure 3.1 Structure of a C++ Program


4/47

A Typical C++ Program

// A typical C++ Program

# include using namespace std;

# define PI 3.142

int Integer;

int main ( ){

double radius, area;

radius = 7;

area = radius * radius * PI;

return 0;}

PreprocessorDirective

Comment

Main

function

Global Declaration

Local declaration

Statements


5/47

Character Set

C++ is composed of character set :

Number : 0 to 9

Alphabetical : a to z and A to Z

Spacing

Special Character :

, . : ; ? ! ( ) {} + - * / = > < # % & ^ ~ | / _


6/47

Token

Token : combination of the characters in C++

Categorised into:

Identifiers

Reserved words/keywords

Constants

Literal String

Punctuators

Operators


7/47

Identifiers

Allows programmers to name data and other objects in theprogram-variable, constant, function etc.

Can use any capitalletter A through Z, lowercase letters athrough z, digits 0 through 9 and also underscore ( _ )

Rules for identifier

The first character must be alphabetic character or underscore

It must consists only of alphabetic characters, digits andunderscores, cannot contain spaces

It cannot duplicate any reserved word

C++ is case-sensitive; this means that CASE, Case, case, andCaSe are four completely different words.


8/47

Valid and Invalid Identifiers

Valid names

A

student_name

_aSystemName

pi

al stdntNm

_anthrSysNm

PI

Invalid names

$sum // $ is illegal

2names // cant start with2

stdnt Nmbr // cant have space

int // reserved word


9/47

Reserved word/Keywords

A word that has special meaning in C++.

Keywords cannot be used to name identifiers.


10/47

Constant

Data values that cannot be changed during the

execution of a program

Types of constant: Literals constant

Defined constants

Declared constants


11/47

Literals Constant

If the data cannot be changed, we can simply codethe data value itself in a statement

Eg: discount = 0.10 ;

Categorised into:

Integer Numerals ( eg: 178, -9, 0113, 0x4b)

Floating-Point Numerals (eg: 3.14159,6.02e23,1.6e-19 ,3.0

Characters ( eg: A, p) Strings ( eg; Hello World)

Boolean (eg: true , false).

0.10 is a literal

constant


12/47

Defined Constant (#define)

Use the #define preprocessor directive

Format: #define identifier value

Eg : #define EPF_RATE 0.11

Placed at the beginning of the program#include using namespace std;#define EPF_RATE 3.142

int main(){

;nett = salary ( salary * EPF_RATE);;

}


13/47

Declared Constants

Use a type const qualifier to indicate that data cannot

be changed and to fix the contents of the memory location

Eg: const float pi = 3.1416;

Declared inside a function

#include using namespace std;#define EPF_RATE 3.142

int main(){

const double socso_rate = 0.05;nett = salary ( salary * EPF_RATE * socso_rate);;

}


14/47

Data Types in C++

Type defines a set of value and operations

that can be applied on those values

Set of values for each type is known as the

domain for the type

Functions also have types which is determinedby the data it returns


15/47

Data Types

Standard

They serves as the basic building blocks for

derived types (compl

ex structures th

at are buil

tusing the standard types

Serves as the basic building blocks for derived

types


16/47

Data Types

Derived


17/47

Data Type : Void

Typed as void

Has no values and operations

Both set of values are empty

Usually used in functions Eg: void printSum()


18/47

Data Type : Char

Used to hold characters or very small integer values

Usually 1 byte of memory

CODE:char letter;

letter = 'C';


19/47

Data Type : Integer

Coded as int

A number without a fraction part

C++ supports three different sizes of integer short int

int

long int

Can be signed and unsigned


20/47

Data Type : Integer

Type Byte Size MinimumValue

Maximum Value

short int 2 -32,768 32,767

unsigned short int 2 0 65,535

int 4 -2,147,483,648 2,147,483,647

unsigned int 4 0 4,294,967,295

long int 4 -2,147,483,648 2,147,483,647

unsigned long int 4 0 4,294,967,295


21/47

Data Type : Float

A number with fractional part such as 43.32, - 2.33

C++ supports three types of float

float

double long float

Stored in a form similar to scientific notation

Can be represented in

Fixed point (decimal) notation:31.4159 0.0000625

E notation:

3.14159E1 6.25e-5


22/47

Data Type Float

Are double by default

Can be forced to be float (3.14159f) or longdouble (0.0000625L)

All floating-point numbers are signed

Type Byte Size Precision Range

float 4 7 10-37 ..1038

double 8 15 10-307 ..10308

long double 8 15 10-307 ..10308


23/47

Data Type : Boolean

Represents values that are true or false

bool variables are stored as small integers

false is represented by 0, true by 1:

bool allDone = true;

bool finished = false;allDone finished

0


24/47

Variables

A storage location in memory whose contents can change whileprogram is running

Has an identifier and a type of data it can hold

Variable declaration syntax :type identifier [= initial_value]

eg : int itemsOrdered;

A variable name should represent the purpose of the variable.

To hold the number of items ordered.


25/47

Variables DIRI KO TAMAN..


26/47

Variables Initialization

To initialize a variable means to assign it a valuewhen it is declared:

int length = 12;

Can initialize some or all variables:

int length = 12, width = 5, area;


27/47

Variables Assignment

An assignment statement uses the = operator to store

a value in a variable.item = 12;

This statement assigns the value 12 to the itemvariable.

The variable receiving the value must appear on theleft side of the = operator.

This will NOT work:// ERROR!12 = item;


28/47

Variables Scope

The scope of a variable: the part of the program in which thevariable can be accessed

A variable cannot be used before it is defined


29/47

Variables Scope

#include using namespace std;#define EPF_RATE 0.11

double nett = 0;bool isEmployee;

int main(){

double salary;

isEmployee = truenett = salary ( salary * EPF_RATE);;

}void printSalary(){int Integer = 150;

cout


30/47

Variables Scope

Global scope

a global variable is a variable declared in the mainbody of the source code, outside all functions

Global variables can be referred from anywhere in thecode, even inside functions, whenever it is after itsdeclaration.

LocalScope

a local variable is one declared within the body of a

function or a block.

is limited to the block enclosed in braces ({}) where they

are declared.


31/47

Operators

C ++ uses a set of built in operators ( Eg : +, -,/ etc).

Four classes of operators :

Arithmetic

Relational

Logical

Assignment


32/47

Arithmetic Operators

Assume int a=4, b= 5, d;

C++

Operation

Arithmetic

Operator

C++

Expression

Value of d

after

assignment

Addition + d = a + b 9

Substraction - d = b - 2 3

Multiplication * d = a * b 20

Division / d = a/2 2

Modulus % d = b%3 2


33/47

Assignment Operators

Assume x=4, y=5, z=8;Assignment

Operator

Sample

Expression

Similar

Expression

Value of variable

after assignment

+= x += 5 x = x + 5 x=9

-= y -= x y = y - x y=1

*= x *= z x = x*z x=32

/= z /=2 z = z/2 z = 4

%= y %=x y = y%x y=1


34/47

Relational & Equality Operators

Assume y = 6, x =5

Relational Operators Sample Expression Value

> y > x T

< y < 2 F

>= x >= 3 T


35/47

Logical Operators

Logical Operators Called Sample Operation

&& AND expression1 && expression 2

| | OR

expression1 | | expression2

! NOT !expression

Example :Assume int x = 50

expression !expression Sample Expression

F T !(x == 60)

T F !(x != 60)


36/47

Logical Operators

Assume x=4, y=5, z=8

expression1 expression2 expression1 &&

expression2

Sample Expression

F F F ( y > 10) && ( z


37/47

Increment and Decrement Operators

Operator Called Sample

Expression

Similar

Expression

Explanation

++ preincrement ++a a = a +1

a += 1

Increment a by 1, then use

the new value of a in

expression in which a reside

++ postincrement a++ a = a +1

a += 1

Use the current value of a in

the expression which a

reside, then increment a by

1

- - predecrement - - a a = a -1

a -= 1

Decrement a by 1, then usethe new value of a in

expression in which a reside

- - postdecrement a - - a = a -1

a -= 1

Use the current value of a in

the expression which a

reside, then decrement a by1


38/47

Operator Precedence

Operators Associative

( ) Left to right

++ - - + - ! Right to left

* / % Left to right

+ - Left to right

< >= Left to right

= = != Left to right

&& Left to right

| | Left to right

*= += - = /= %= Right to left


39/47

Operator Precedence

Example 1:

int a=10,b=20, c=15, d=8;

a*b/(-c*31%13)*d

1. a*b/(-15*31%13)*d

2. a*b/(-465%13)*d

3. a*b/(-10)*d

4. 200/(-10)*d5. -20*d

6. -160

Example 2:

int a=15, b=6, c=5, d=4;

d *= ++b a/3 + c

1. d *= ++b a/3+ c

2. d*=7- a/3+c

3. d*=7- 5+c

4. d*=2 + c5. d*= 7

6. d = d*7

7. d = 28


40/47

Example of a program

// Operating with variables

#include using namespace std;

int main(){

//variables declarationint no1;

int no2;int value_div;int value_mod;

cout > no1 >> no2;value_div= no1 / no2;

cout


41/47

/*Evaluate two complex expression*/

#include

using namespace std;

void main ( )

{

int a =3, b=4, c = 5, x, y;

cout


42/47

Formatting Output

Output is made more readable using manipulator

Must include header file.

Manipulators Use

endl

dec

oct

hex

fixedshowpoint

setw()

setprecision

setfill()

New line

Formats output as decimal

Formats output as octal

Formats output as hexadecimal

Set floating-point decimalsShows decimal in floating-point values

Sets width of output fields

Specifies number of decimals for floating point

Specifies fill character


43/47

Formatting Output

Set Width (setw)

Set the minimum width for an output

Two alignment : right justified and left justified

Set Fill Character (setfill)

If the output width is greater than the data valuesplaced in it, a fill character can be used to fill theempty spaces whenever required


44/47

Formatting Output

Three integer manipulators:

Decimal (dec)

The default

Value in decimal form

Octal (oct)

Values are displayed in octal numbering system

Hexadecimal (hex)

Values are in hexadecimal format


45/47

Formatting Output

Three Floating-point manipulators:

Fixed (fixed)

Displays floating-point numbers (eg: 1.234568e+6) in

the fixed-point format (1234567.875)

Set precision (setprecision)

Used to control the number of the decimal places to be

displ

ayed Showpoint (showpoint)

To show value with the decimal point


46/47

46

//demonstrate the output manipulator

#include

#include

using namespace std;

int main( )

{

char aChar;

int integer;

float dlrAmnt;

cout integer>>dlrAmnt >> aChar;

cout


47/47

THANK YOU!

MELJUN CORTES--IT102 Introduction to C Programming Complete

Documents

Transcript of MELJUN CORTES--IT102 Introduction to C Programming Complete