Object-Oriented Programming Using C++

Object-Oriented Programming Using C++ CLASS 16

Objectives • Create a function that supports parameters of a later-determined type • Use class templates to create a group of related types • Understand the difference between a class template and a templated class

Template Functions template <class T> void printArray(const T *array, const int count) { for (int i = 0; i < count; i++) cout << array[i] << “ ’; cout << endl; } Pg. 650

Template Functions template <class T> void printArray(const T *array, const int count) { for (int i = 0; i < count; i++) cout << array[i] << “ ’; cout << endl; } main( ) { int a[5] = { 1, 2, 3, 4, 5}; printArray(a, 5); Pgs. 650 and 651

Template Functions template <class T> void printArray(const T *array, const int count) { for (int i = 0; i < count; i++) cout << array[i] << “ ’; cout << endl; } main( ) { int a[5] = { 1, 2, 3, 4, 5}; printArray(a, 5); char c[6] = “HELLO”; printArray (c, 6); Pg. 651

Function Template Supporting 2 Types template < class T1, class T2> int sum (T1 *array, T2 value, int num-elements) { T2 sum = 0; for(int i = 0; i < num_elements; i++) sum + = array [i]; } main( ) { int values[ ] = {1, 2, 3, 4}; long int total = 0; sum(values, total, 4); cout << “total is” << total; } Pg. 652

Function Template Supporting 2 Types template < classT1, class T2> int sum (T1 *array, T2 value, int num-elements) { T2 sum = 0; for(int i = 0; i < num_elements; i++) sum + = array [i]; } main( ) { int values[ ] = {1, 2, 3, 4}; long int total = 0; sum(values, total, 4); cout << “total is” << total; } Pg. 652

Class Templates-Parameterized Types Pgs. 653 and 654 #ifndef TSTACK1_H #define TSTACK_H #include <iostream.h> template< class T > class Stack { public: Stack( int = 10 ); ~Stack( ) { delete [ ] stackPtr; } bool push( const T& ); bool pop( T& ); private: int size; int top; T *stackPtr; bool isEmpty( ) const { return top == -1; } bool isFull( ) const { return top == size - 1; }

Class Templates-Parameterized Types Pgs. 653 and 654 #ifndef TSTACK1_H #define TSTACK_H #include <iostream.h> template< class T > class Stack { public: Stack( int = 10 ); ~Stack( ) { delete [ ] stackPtr; } bool push( const T& ); bool pop( T& ); private: int size; int top; T *stackPtr; bool isEmpty( ) const { return top == -1; } bool isFull( ) const { return top == size - 1; } type symbol templatekeyword

Class Templates-Parameterized Types Pgs. 653 and 654 #ifndef TSTACK1_H #define TSTACK_H #include <iostream.h> template< class T > class Stack { public: Stack( int = 10 ); ~Stack( ) { delete [ ] stackPtr; } bool push( const T& ); bool pop( T& ); private: int size; int top; T *stackPtr; bool isEmpty( ) const { return top == -1; } bool isFull( ) const { return top == size - 1; } Using theType Symbol

Stack Operations push - add a plate

Stack Operations push - add a plate pop - remove a plate

Stack Operations Push - add a plate pop - remove a plate is empty - there are no plates

Stack Operations Push - add a plate pop - remove a plate is empty - there are no plates is full - no more room in cabinet

Stack as an array of integers top -1 size 8

Stack as an array of integers top 0 size 8 5 Push (5)

Stack as an array of integers top 1 size 8 5 9 Push (5) Push (9)

Stack as an array of integers top 2 size 8 5 9 3 Push (5) Push (9) Push (3)

Stack as an array of integers top 1 size 8 5 9 Push (5) Push (9) Push (3) Pop

Stack as an array of integers top 0 size 8 5 Push (5) Push (9) Push (3) Pop Pop

Templates - Constructor // Constructor with default size 10 template<class T> Stack<T>::Stack(int s) { size = s > 0 && s < 1000 ? s: 10; top = -1; stackPtr = new T[size]; } Pg. 654

Templates - Push // Push an element onto the Stack // return 1 if successful, 0 otherwise template<class T> bool Stack<T>::push(const T &pushValue) { if (!isFull( ) ) { stackPtr[++top] = pushValue; return true; } return false; } Pg. 654

Templates - Pop // Pop an element off the Stack templat<class T> bool Stack<T>::pop(T &popValue) { if (!isEmpty( ) ) { popValue = stackPtr[top- -]; return true; } return false; } #endif Pg. 654

Templates main ( ) { Stack<double>doubleStack (5); double f = 1.1; while (doubleStack.push (f)) { cout << f; f + = 1.1; } while (doubleStack.pop (f) cout << f; }

Templates Class Name main ( ) { Stack<double>doubleStack (5); double f = 1.1; while (doubleStack.push (f)) { cout << f; f + = 1.1; } while (doubleStack.pop (f) cout << f; }

Templates Class Name Object Type main ( ) { Stack<double>doubleStack (5); double f = 1.1; while (doubleStack.push (f)) { cout << f; f + = 1.1; } while (doubleStack.pop (f) cout << f; }

Templates Class Name Object Type main ( ) { Stack<double>doubleStack (5); double f = 1.1; while (doubleStack, push (f)) { cout << f; f + = 1.1; } while (doubleStack.pop (f) cout << f; } Desired Stack Size

Q & A

Object-Oriented Programming Using C++