Introduction to c ++ part -1

Recall

• What are files handling used for?

• How do we write in to a file?

• What are the different modes of opening a

file?

• What is fgetc() ?

Introduction to C++Week 4- day 1

C++

• Super Set of CC++ was originally developed to be the next version of C, not a new language.

• Backward compactable with C

Most of the C functions can run in C++

• Same compiler preprocessorMust have a function names “main” to determine where the program starts

Where they born

Bell Labs

C Vs C++Similarities

C Vs C++

• int

• Char

• Float

• double

“Exactly the same as

of left side”

Data Types

C Vs C++

• Conditional control

structures– If

– If else

– Switch

• Loops– for

– while

– Do while


of left side”

Control Structures

C Vs C++

int sum(int a, int b)

{

Int c;

c=a + b

return c;

}

sum(12,13)


of left side”

functions

C Vs C++

Int a[10];

Int b[] = {1000, 2, 3,

50}; “Exactly the same as

of left side”

Arrays

C Vs C++Differences

C Vs C++

Output

printf(“ value of a = %d”,a);

Printf(“a = %d and b= %d”,a,b);

Input

scanf(“%d ", &a);

Scanf(“%d”,&a,&b);

Output

cout<< “value of a =" << a;

Cout<<“a =”<<a<<“b=”<<b;

Input

cin>>a;

Cin>>a>>b;;

Input / Output

C Vs C++

char str[10];

str = "Hello!"; //ERROR

char str1[11] = "Call

home!";

char str2[] = "Send

money!";

char str3[] = {'O', 'K',

'\0'};

strcat(str1, str2);

strcpy(str, "Hello!");

string str;

str = "Hello";

string str1("Call

home!");

string str2 = "Send

money!";

string str3("OK");

str = str1 + str2;

str = otherString;

Strings

C Vs C++

struct Data

{

int x;

};

struct Data module;

module.x = 5;

struct Data

{

int x;

void printMe()

{

cout<<x;

}

} Data;

Data module,Module2;

module.x = 5;

module2.x = 12;

module.printMe() // Prints 5

module.printMe() // Prints 12

Structures

What’s New in C++ ?

• OOP concepts

• Operator overloading

What’s New in C++ ?

OOP Concept

• Object-oriented programming (OOP) is a

style of programming that focuses on

using objects to design and build

applications.

• Think of an object as a model of the

concepts, processes, or things in the real

Objects in real World

Real World Objects

Objects in real world

• Object will have an identity/name

Eg: reynolds, Cello for pen. Nokia,apple for

mobile

• Object will have different properties which

describes them best

Eg:Color,size,width

• Object can perform different actions

Eg: writing,erasing etc for pen. Calling,

texting for mobile

Objects

I have an identity: I'm Volkswagen

I have different properties.My color property is green

My no:of wheel property is 4

I can perform different actionsI can be drived

I can consume fuelI can play Music

I have an identity: I'm Suzuki

I have different properties.My color property is silver

My no:of wheel property is 4

I can perform different actionsI can be drived

I can consume fuelI can play Music

How these objects are created?

• All the objects in the real world are created

out of a basic prototype or a basic blue

print or a base design

Objects in software World

Objects in the software world

• Same like in the real world we can create

objects in computer programming world

– Which will have a name as identity

– Properties to define its behaviour

– Actions what it can perform

How these objects are

created• We need to create a base design which

defines the properties and functionalities

that the object should have.

• In programming terms we call this base

design as Class

• Simply by having a class we can create

any number of objects of that type

Definition

• Class : is the base design of

objects

• Object : is the instance of a class

• No memory is allocated when a class is

created.

• Memory is allocated only when an object is

created.

How to create class in

C++class shape

{

Int width;

Int height;

Int calculateArea()

{

return x*y

}

}

public:


C++class shape

{

Int width;

Int height;

Int calculateArea()

{

return x*y

}

}

Is the Keyword to create any class

public:


C++class shape

{

Int width;

Int height;

Int calculateArea()

{

return x*y

}

}

Is the name of the class

public:


C++class shape

{

Int width;

Int height;

Int calculateArea()

{

return x*y

}

}

Called access specifier. Will detailed soonpublic:


C++class shape

{

Int width;

Int height;

Int calculateArea()

{

return x*y

}

}

Are two variable that referred as the properties

public:


C++class shape

{

Int width;

Int height;

Int calculateArea()

{

return x*y

}

}

Is the only functionality of this class

public:

How to create objects in

C++shape rectangle,square;

rectangle.width=20;

recangle.height=35;

square.height=10;

square.width=10;

rArea=rectangle.calculateArea();

sArea=square.calculateArea();

Is the class name



rectangle.width=20;

recangle.height=35;

square.height=10;

square.width=10;



Two objects of base type shape



rectangle.width=20;

recangle.height=35;

square.height=10;

square.width=10;



Setting properties of object named rectangle



rectangle.width=20;

recangle.height=35;

square.height=10;

square.width=10;



Setting properties of object named square



rectangle.width=20;

recangle.height=35;

square.height=10;

square.width=10;



Calling the functionality of rectangle which is claclulateArea();



rectangle.width=20;

recangle.height=35;

square.height=10;

square.width=10;


sArea=square.calculateArea();Calling the functionality of rectangle which is claclulateArea();

Example

Class : shape

Height:35 width:20

Object rectangle

calculateArea(){Return 20*35}

Height:10 width:10

Object square

calculateArea(){Return 10*10;}

Member variablesHeightwidth

Member functioncalculateArea{return height*width;

}

Access Specifier

• Access specifiers defines the access

rights for the statements or functions that

follows it until another access specifier or

till the end of a class.

• The three types of access specifiers are

– Private

– Public

– Protected

Access Specifier

class Base

{

public:

// public members go here

protected:

// protected members go here

private:

// private members go here

};

Class Vs Structure

• Class is similar to Structure.

• Structure members have public access by

default.

• Class members have private access by

default.

Self Check !!

Self Check

• Which of the following term is used for a

function defined inside a class?

– Member Variable

– Member function

– Class function

– Classic function

Self Check

• Which of the following term is used for a

function defined inside a class?

– Member Variable

– Member function

– Class function

– Classic function

Self Check

• cout is a/an __________ .

– Operator

– Function

– Object

– macro

Self Check

• cout is a/an __________ .

– Operator

– Function

– Object

– macro

Self Check

• Which of the following is correct about

class and structure?

– class can have member functions while

structure cannot.

– class data members are public by default

while that of structure are private.

– Pointer to structure or classes cannot be

declared.

– class data members are private by default

while that of structure are public by default.

Self Check

• Which of the following is correct about

class and structure?

– class can have member functions while

structure cannot.

– class data members are public by default

while that of structure are private.

– Pointer to structure or classes cannot be

declared.

– class data members are private by default

while that of structure are public by default.

Self Check

• Which of the following operator is

overloaded for object cout?

• >>

• <<

• +

• =

Self Check

• Which of the following operator is

overloaded for object cout?

• >>

• <<

• +

• =

Self Check

• Which of the following access

specifier is used as a default in a

class definition?

• protected

• public

• private

• friend

Self Check

• Which of the following access

specifier is used as a default in a

class definition?

• protected

• public

• private

• friend

End of Day

Technology

Introduction to c ++ part -1