603a.cpp

C++实训教程

/*
	603a.cpp
	a Array class,using operator[] overload
    demo a safe array !!自定义数组的安全性
*/
   
#include <iostream.h>
#include <stdlib.h>

class Array
{
	long * p;
    int size;
  public:
    Array(int n){	p = new long[n];  size = n;}
	 ~Array() {delete [] p;}
    long& operator [] (int i)
    {
    	if (i<0 || i>=size)
		{
			cerr<<"Array index is over bound!\n";
			exit(1); // #include <stdlib.h>
		}
      return p[i];
    }
};

main()
{
    const SIZE = 4;
    Array  a(SIZE);
    int i;
    for (i = 0; i < SIZE; i++)   a[i] = i*i;
    for (i = 0; i < SIZE; i++)   cout << a[i] << "  ";
    cout << endl;
    cout << a[SIZE] ;
    
	 return 0;
}
/*output: BC50 v.03
0  1  4  9
Array index is over bound!


*/