关于二维数组,指针运算问题,注意二维指针需要解两次引用,即第 0 个元素是 *(*a)。见下例:
#include <iostream>
using namespace std;
int main() {
int a[3][7];
int count = 1;
for (int i = 0; i < 3; ++i) {
for (int j = 0; j < 7; ++j) {
a[i][j] = count++;
}
}
/*
* 1 2 3 4 5 6 7
* 8 9 10 11 12 13 14
* 15 16 17 18 19 20 21
*/
cout << "a: " << a << endl; // 00000043DB1DF9B0
cout << "*a: " << *a << endl; // 00000043DB1DF9B0
cout << "a+1: " << a+1 << endl; // 00000043DB1DF9CC
cout << "*(a+1): " << *(a+1) << endl; // 00000043DB1DF9CC
cout << "*(*(a+1)): " << *(*(a+1)) << endl; // 8
cout << "*a + 1: " << *a + 1 << endl; // 00000043DB1DF9B4
cout << "*(*a + 1): " << *(*a + 1) << endl; // 2
// -336980848,两者结果相同
cout << "*(a+1)[5]: " << *(a+1)[5] << endl; // *(a+1)[5] == * ((a+1)[5]) == *(*(a+1+5))
cout << "*(*(a+1+5)): " << *(*(a+1+5)) << endl; // *(a+1)[5] == * ((a+1)[5]) == *(*(a+1+5))
cout << "*(a+1) + 5: " << *(a+1) + 5 << endl; // 00000043DB1DF9E0
cout << "*(*(a+1) + 5):" << *(*(a+1) + 5) << endl; // 13
cout << *(*a+3) << endl; // 4
cout << *(*(a+1)) << endl; // 8
cout << *(&a[0][0] + 2) << endl; // 3
return 0;
}