Question

How to achieve compile time polymorphism explain in detail.

Answer 1

The process of linking of function call to function definition at compile time is called as Compile Time Polymorphism. It can be through Function and operator overloading.

Function overloading: The process of defining the function with same name but with different number or type of argument is known as Function Overloading. In function Overloading, the function would perform different operations depending on the argument list in the function call. The correct function to invoked is determined at compile time by checking the number and type of the arguments but not on the function return type.

Example:

Function Overloading:

Swapping of two integers and swapping of two float values.

// Function definition1- swapping two integers

void swap(int*p, int*q)

{

int t;

t=*p;

*p=*q;

*q=t;

}

// Function definition2- swapping two floats

void swap(float*p,float*q)

{

float t;

t=*p;

*p=*q;

*q=t;

}

For the function call swap (&a, &b) where a and b are integers and function definition1 will be executed and function definition2 for the function call as swap (&a, &b) when a and b are floats.

OR

Operator Overloading: The Process of defining operator function to extend the use of existing operator to operate on User-defined data type such as „object of class‟ is known as Operator Overloading.

Example: Overloading + operator to concatenate two strings.

class string1

{

char str[20];

public:

void getdata()

{

cout<<"\n Enter String :";

cin>>str;

}

void display()

{

cout<<str;

}

void operator+(string1 x) //Concatenating String

{

strcat(str,x.str);

}

};

void main()

{

string1 str1, str2;

clrscr();

str1.getdata();

str2.getdata();

str1+str2;

cout<<"\n\n Concatenated String is:";

str1.display();

getch();

}