C++创建二维指针问题

Question

int n = 0;
int **num = new int*[n];
cin >> n;

上述的代码，Line2和Line3我弄反了，为什么结果在后面进行二维数组操作的时候没有影响?

for (int i = 0; i<n; i++) {
        num[i] = new int[i+1];
        for (int j = 0; j < i+1; j++) {
            cin >> num[i][j];
        }
    }

比如我上述操作之后，我还是可以对num[][]进行读写。new的性质到底是怎样的？

Answer 1

C and C++ do not detect out-of-bounds arrays of basic types. You can play around with pointers, but doing so is dangerous