Illustrate the example of constructor, C/C++ Programming

Assignment Help:

A Constructive Example

Consider an example , to model a user-defined data type for  strings. The object simulates a character array ( string ) using a character pointer and an integer variable for its actual size, which can be explained at its run-time. The object doesn't use a character array , as it may impose a limit on the number of characters that can be stored.

e.g.

# include

# include < string.h>

class string

                 {

                  public :

                                string ( char *s);

                                ~string();

                                void putstr();

                  private :

                                char *cptr;

                                int size;

 };

void main(void)

                 {

                  string s1(" Hello student    \n");

                  string s2 = " Welcome to C++   \n";

                  string s3 = string ( " its fun \n");

 

s1.putstr();

                s2.putstr();

                s3.putstr();

 }

 

string::string(char *s)

                 {

                                size = strlen(s);

                                cptr = new char[size + 1];

                                strcpy(cptr,s);

                 }

string::~string()

                 {

                                delete cptr;

                 }

void string::putstr()

                 {

                                cout << cptr;

                 }

The class explained in the above example contains a character pointer, which allocates memory at run-time, after determining the actual size need. This programme demonstrates the use of class along with the constructor and destructor to make a user defined data type String. The constructor function contains a default argument of null character, which will be assigned to the variable cptr in the absence of an actual parameter. The destructor uses the delete operator to release the memory allocated by the constructor .

 


Related Discussions:- Illustrate the example of constructor

Integral, Write a program to find the area under the curve y = f(x) between...

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b

Beti, how is a beti a beti

how is a beti a beti

Define classes and objects, Classes and Objects A class is a vehicle to...

Classes and Objects A class is a vehicle to execute the OOP features in the C++ language. Once a class is declared, an object of that type can be explained. An object is said t

Explain input output function, Input Output Most languages have "statem...

Input Output Most languages have "statements" to perform I/O . Though in C and C++ we use "functions" to perform I/O. C++ also has its own I/O mechanism - the cin and cout obje

Program to draw a circle - c program, Program to draw a circle: int ma...

Program to draw a circle: int main(void) {    /* request auto detection */    int gdriver = DETECT, gmode, errorcode;    int midx, midy;    int radius = 100;

Describe overloading??, A: Along with the C++ language, you can overload op...

A: Along with the C++ language, you can overload operators and functions. Overloading is the practice of supplying more than one definition for a provided function name in the same

Algorithm , write an algorithm to swap values without using third variable

write an algorithm to swap values without using third variable

Write a program to act as an electronic safe, Write a program to act as an ...

Write a program to act as an electronic safe. If the correct code has been entered the program should display "Safe Open".  If an incorrect code is input it should display "Alarm"

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd