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

Dynamic memory management, C and C++ require explicit dynamic memory manage...

C and C++ require explicit dynamic memory management, using new and delete or malloc() and free(). It is helpful to understand where variables exist (usually the stack or the he

What is the use of default constructor, What is the use of default construc...

What is the use of default constructor? - It's a constructor that doesn't accept any parameters. - If there is no user-defined constructor for a class, compiler declares a d

Program is to append the contents of one file to another, Program is to app...

Program is to append the contents of one file to another: void main()    {   clrscr();   fstream file1,file2;   char st1[13],st2[13];/* 13 because a filename canno

Nested if else, input marks of c and c++ if c grater than equal to 50 grate...

input marks of c and c++ if c grater than equal to 50 grater than 50 you are pass if c greater than equal to 50 c++ less than 50 than supplementry c++ if c less then 50 and c++ gra

Substitution model, (a) Write a procedure called (mult x y) that multiplies...

(a) Write a procedure called (mult x y) that multiplies two numbers x and y in a recursive manner using successive addition. Specifically, note that a x b = a + a + .... + a (b tim

Sums a sequence of integers, assume that the first integer read with cin sp...

assume that the first integer read with cin specifies the number of values remaining to be entered. that program should read only one value each time cin is executed .a typical inp

How to create a data file, How to Create A Data File? A data file shoul...

How to Create A Data File? A data file should be created before it can be processed. A stream-oriented data file is able to be created in two ways. One is to create the file st

Eevrv, Ask question #Mi fd d fffffffffffffffffffffffffffffffffffffffffff...

Ask question #Mi fd d fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff

Padovan string, find the occurence of zy in the final string

find the occurence of zy in the final string

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