下标运算符重载

重载该运算符用于增强操作C++数组的功能。

/***
subscript.cpp
***/
#include<iostream>
using namespace std;
const int SIZE = 10;class safearay
{private:int arr[SIZE];public:safearay(){register int i;for(i = 0; i < SIZE ;i++){arr[i] = i;}   }int& operator[](int i){if(i > SIZE){cout << "the index is too big" << endl;return arr[0];}return arr[i];}
};int main()
{safearay A;cout << "A[2] = " << A[2] << endl;cout << "A[5] = " << A[5] << endl;cout << "A[12] = " << A[12] << endl;return 0;
}

运行结果：

exbot@ubuntu:~/wangqinghe/C++/20190809$ g++ subscript.cpp -o subscript

exbot@ubuntu:~/wangqinghe/C++/20190809$ ./subscript

A[2] = 2

A[5] = 5

the index is too big

A[12] = 0