// Fig 18.4: array1.cpp // Member function definitions for class Array #include using std::cout; using std::cin; using std::endl; #include using std::setw; #include #include #include "array1.h" // Initialize static data member at file scope int Array::arrayCount = 0; // no objects yet // Default constructor for class Array (default size 10) Array::Array( int arraySize ) { size = ( arraySize > 0 ? arraySize : 10 ); ptr = new int[ size ]; // create space for array assert( ptr != 0 ); // terminate if memory not allocated ++arrayCount; // count one more object for ( int i = 0; i < size; i++ ) ptr[ i ] = 0; // initialize array } // end Array constructor // Copy constructor for class Array // must receive a reference to prevent infinite recursion Array::Array( const Array &init ) : size( init.size ) { ptr = new int[ size ]; // create space for array assert( ptr != 0 ); // terminate if memory not allocated ++arrayCount; // count one more object for ( int i = 0; i < size; i++ ) ptr[ i ] = init.ptr[ i ]; // copy init into object } // end Array constructor // Destructor for class Array Array::~Array() { delete [] ptr; // reclaim space for array --arrayCount; // one fewer objects } // end Array destructor // Get the size of the array int Array::getSize() const { return size; } // Overloaded assignment operator // const return avoids: ( a1 = a2 ) = a3 const Array &Array::operator=( const Array &right ) { if ( &right != this ) { // check for self-assignment // for arrays of different sizes, deallocate original // left side array, then allocate new left side array. if ( size != right.size ) { delete [] ptr; // reclaim space size = right.size; // resize this object ptr = new int[ size ]; // create space for array copy assert( ptr != 0 ); // terminate if not allocated } // end if for ( int i = 0; i < size; i++ ) ptr[ i ] = right.ptr[ i ]; // copy array into object } // end if return *this; // enables x = y = z; } // end operator= function // Determine if two arrays are equal and // return true, otherwise return false. bool Array::operator==( const Array &right ) const { if ( size != right.size ) return false; // arrays of different sizes for ( int i = 0; i < size; i++ ) if ( ptr[ i ] != right.ptr[ i ] ) return false; // arrays are not equal return true; // arrays are equal } // end operator== function // Overloaded subscript operator for non-const Arrays // reference return creates an lvalue int &Array::operator[]( int subscript ) { // check for subscript out of range error assert( 0 <= subscript && subscript < size ); return ptr[ subscript ]; // reference return } // end operator[] function // Overloaded subscript operator for const Arrays // const reference return creates an rvalue const int &Array::operator[]( int subscript ) const { // check for subscript out of range error assert( 0 <= subscript && subscript < size ); return ptr[ subscript ]; // const reference return } // end operator[] function // Return the number of Array objects instantiated // static functions cannot be const int Array::getArrayCount() { return arrayCount; } // Overloaded input operator for class Array; // inputs values for entire array. istream &operator>>( istream &input, Array &a ) { for ( int i = 0; i < a.size; i++ ) input >> a.ptr[ i ]; return input; // enables cin >> x >> y; } // end operator>> function // Overloaded output operator for class Array ostream &operator<<( ostream &output, const Array &a ) { int i; for ( i = 0; i < a.size; i++ ) { output << setw( 12 ) << a.ptr[ i ]; if ( ( i + 1 ) % 4 == 0 ) // 4 numbers per row of output output << endl; } if ( i % 4 != 0 ) output << endl; return output; // enables cout << x << y; } // end operator<< function /************************************************************************** * (C) Copyright 1992-2004 by Deitel & Associates, Inc. and * * Pearson Education, Inc. All Rights Reserved. * * * * DISCLAIMER: The authors and publisher of this book have used their * * best efforts in preparing the book. These efforts include the * * development, research, and testing of the theories and programs * * to determine their effectiveness. The authors and publisher make * * no warranty of any kind, expressed or implied, with regard to these * * programs or to the documentation contained in these books. The authors * * and publisher shall not be liable in any event for incidental or * * consequential damages in connection with, or arising out of, the * * furnishing, performance, or use of these programs. * *************************************************************************/