Container Class and Integrators, Proxy Class EC6301-OOPS AND DATA STRUCTURES

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Jeffry Summers
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1 Container Class and Integrators, Proxy Class

2 Container Class A container class is a data type that is capable of holding a collection of items. A container stores many entities and provide sequential or direct access to them. List, vector and strings are such containers in standard template library. Various operations associated with container class are: Create an empty container Insert an object inside the container Remove an object from container Find the number of objects in the container Sort the objects within the container

3 Components of STL

4 Container class Categories of container class: Sequence containers Associative containers Container adapters Sequence container: container class that maintain the ordering of elements in the container. Types of Sequence containers: Vector :dynamic array capable of growing,allows random access to its element. Deque: deck, double ended queue, grow from both sides List: Doubly linked list

5 Container class Associative containers: automatically sort their inputs when those inputs are inserted into the container. Associative containers compare elements using operator <. Types of associative containers: Multiset- duplicate elements are allowed Map(associative array)- key/value pair Multimap(dictionary)-is a map that allows duplicate keys.(key word, value-meaning)

6 Container class Container adapters: predefined containers that are adapted to specific uses. Stack : LIFO,operations done at end of the container Queue: FIFO, Insertion: back of the container, Deletion: front Priority queue

7 Container class Iterator It is an object that can traverse a container class without the user having to know how the container is implemented.

8 Container class #include<iostream.h> #include<conio.h> class bag public: void insert(int); void show(); int size(); bag()count=0;} private: int data[20]; int count; };

9 Container class void bag::insert(int val) data[count]=val; count++; } void bag::show() for(int i=0;i<count;i++) cout<<" "<<data[i]; } int bag::size() return count; }

10 Container class void main() bag o; clrscr(); cout<<"\nthe items in container are:\n"; o.insert(20); o.insert(40); o.insert(60); o.show(); cout<<"\n size of the container"<<o.size(); cout<<"\n items in container are\n"; o.insert(80);

11 Container class o.insert(100); o.show(); cout<<" \n size of container is"<<o.size(); cout<<"\n"; getch(); }

12 Container class

13 Proxy Class Proxy class: Used to hide implementation details of a class Class that knows only the public interface of the class being hidden Enables clients to use class services without giving access to class s implementation Forward class declaration: Used when class definition only uses a pointer to another class Prevents the need for including header file Declares a class before it is referenced

14 Proxy Class: Creation of myclass.h class myclass private: int value; public: myclass(int v):value(v) } void setvalue(int v) value=v; } int getvalue() return value; } };

15 Proxy Class:myinterface.cpp class myclass; class myinterface private: myclass *ptr; public: myinterface(int); void setvalue(int); int getvalue(); ~myinterface(); };

16 Proxy Class: Creation of Myinterface.cpp #include"c:\turboc4\tc\bin\myinterf.h" #include"c:\turboc4\tc\bin\myclass.h" myinterface::myinterface(int v):ptr(new myclass(v)) } void myinterface::setvalue(int v) ptr->setvalue(v); } int myinterface::getvalue() return ptr->getvalue(); }

17 Proxy Class :Creation of Myinterface.cpp myinterface::~myinterface() delete ptr; }

18 Proxy Class: Creation of test.cpp #include<iostream.h> #include"c:\tc\bin\myinterf.h" void main() myinterf obj(10); cout<<"\n interface contains(before):"<<obj.getvalue(); obj.setvalue(20); cout<<"\n interface contains(after):"<<obj.getvalue(); }

Standard Template Library

Standard Template Library The standard template library (STL) contains CONTAINERS ALGORITHMS ITERATORS A container is a way that stored data is organized in memory, for example an array of elements. Algorithms