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MEMORYALLOCATION

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Memory Allocation for Objects

Memory space for objects is allocated when

they are declared & not when the class is

specified.

Is it TRUE?

All the objects belonging to that class use the

same member functions, no separate space

is allocated for member functions when theobjects are created.

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Static Data Members

A data member of a class can be

qualified as static.

The properties of a static membervariable are similar to that of a C static

variable.

Used to maintain values common to the

entire class.

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Static Data Members Contd

Characteristics

It is initialized to zero when the first

object of its class is created. No other initialization is permitted.

Only one copy of that member is created

for the entire class & is shared by all the

objects of that class.

No matter how many objects are created.

Visible only within the class.

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Example of static data member#include

#include

class abc

{

static int count; //static data member

int number; //non static memberpublic:

void getdata(int a) //function declaration

{ number = a;

count ++;

}

void getcountI(void)

{ cout

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Contdint item :: count; //definition of static data member

int main()

{ item a, b, c ; //count is initiated to zero

a.getcount(); //display count

b.getcount();

c.getcount();

a.getdata(20); //getting data into object a, b, c

a.getdata(30);

a.getdata(40); output:

cout

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Static Member Functions

A member function i.e. Declared static has the following

properties:-

A static function can have access to only other static

members (functions or variables) declared in the sameclass.

static void getdata() //static member function

A static member function can be called using the class

nameclass_name :: function_name

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Arrays of Objects

Array of any data type including struct.

Array of variables that are of the type class.Such variables are called

arrays of objects.class emp

{

char name[20];

float age;public:

void getdata(void);

void putdata(void);

};

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Objects as FunctionArguments

An object may be used as a function argument.

This can be done in two ways: -

A copy of the entire object is passed to thefunction pass by value

Only the address of the object is transferred

to the function pass by reference

Pass by reference method is more efficient.

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Example: -#include

#includeclass time

{

int hours; //variables declaration

int minutes;public:

void gettime(int h, int m) //function declaration

{ hours = h; minutes = m; }

void putdata(void)

{ cout

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Example: -void time :: sum(time t1, time t2) //t1 & t2 are objects

{ minutes = t1.minutes + t2.minutes;hours = minutes/60;

minutes = minutes%60;

hours = hours + t1.hours + t2.hours;

}

int main()

{ time x, y, z;

x.gettime(2,45);

y.gettime(3,30);

z.sum(x,y); //z=x+ycout

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Thanks!!!