C++ 数组

1 二维数组

int ii[2][3] = {{1, 2, 3},{4, 5, 6}};
    for (auto p = begin(ii); p != end(ii); ++p) {
        for (auto q = begin(*p); q != end(*p); ++q) {
            cout << *q << ' ';
        }
        cout << endl;
    }

2 类型别名

// using int_arry = int[3];  // 类型别名的声明
    typedef int int_arry[3];    // 等价的 typedef 声明
    for (int_arry *p = ii; p != ii + 2; ++p) {
        for (int *q = *p; q != *p + 3; ++q) {
            cout << *q << ' ';
        }
        cout << endl;
    }

3 vector

vector<int> v = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
for (auto &r : v)
    r *= 2;

4 数组做函数参数

// const int ia[] 等价于 const int *ia
void print(const int ia[], size_t size) {
    for (size_t i = 0; i != size; ++i) {
        cout << ia[i] << endl;
    }
}

int j[] = {0, 1};
print(j, end(j) - begin(j));

5 数组引用形参

// &arr 两端括号不可少
void print(int (&arr)[2]) {
    for (auto elem : arr) {
        cout << elem << endl;
    }
}

int j[] = {0, 1};
print(j);