Operation on String - C ++ Program:

Write a program to define operations on string in c++.

class String {

   char *char_ptr;   // pointer to string contents

   int length;       // length of string in characters

public:

   // three different constructors

   String(char *text);           // constructor using existing string

   String(int size = 80);        // creates default empty string

   String(String& Other_String); // for assignment from another

                                 // object of this class

   ~String() {delete char_ptr;};

   int Get_len (void);

   void Show (void);

};

String::String (char *text)

{

   length = strlen(text);  // get length of text

   char_ptr = new char[length + 1];

   strcpy(char_ptr, text);

};

String::String (int size)

{

   length = size;

   char_ptr = new char[length+1];

   *char_ptr = '\0';

};

String::String (String& Other_String)

{

   length = Other_String.length;       // length of other string

   char_ptr = new char [length + 1];   // allocate the memory

   strcpy (char_ptr, Other_String.char_ptr); // copy the text

};

int String::Get_len(void)

{

   return (length);

};

void String::Show(void)

{

   cout << char_ptr << "\n";

};

main ()                                // test the functions

{

   String AString ("Allocated from a constant string.");

   AString.Show();

   String BString;             // uses default length

   cout << "\n" << BString.Get_len() << "\n" ; //display length

   BString = "This is BString";

   String CString(BString);    // invokes the third constructor

   CString.Show();             // note its contents

}