数组容器的操作

#include<iostream>
#include<array>
#include<exception>


void display(std::array<int, 10> &arr)
{
    for (size_t i{}; i < arr.size(); ++i)  //size_t代表unsigned int， i{} 相当于 i = 0， {}也可以对容器内部所有元素赋上初值0
    {
        std::cout << arr[i] << " ";
    }
    std::cout << std::endl;
}
void test01()
{
    std::array<int, 10> volumn;
    volumn.fill(5);  //容器内所有都填入同样的数值
    display(volumn);

    try
    {
        volumn.at(10);  //会抛出异常，而采用[]的方式会直接访问越界导致程序崩溃。
    }
    catch (std::exception &e)
    {
        std::cout << "out of bound" << std::endl;
    }

    if (volumn.empty())  //判断容器是否为空
    {
        std::cout << "the container has no elements" << std::endl;
    }
    else
    {
        std::cout << "the container has " << volumn.size() << " elements" << std::endl;
    }
    
    /*C11的遍历方式，atuo可以自动识别出数据类型，必须通过引用才能修改值*/
    int start = 1;
    for (auto &value : volumn)
    {
        value = start;
        ++start;
    }

    /*使用迭代器*/
    for (std::array<int, 10>::iterator vt = volumn.begin(); vt != volumn.end(); ++vt)
    {
        std::cout << *vt << " ";
    }
    std::cout << std::endl;

    /*使用反向迭代器*/
    for (std::array<int, 10>::reverse_iterator vt = volumn.rbegin(); vt != volumn.rend(); ++vt)
    {
        std::cout << *vt << " ";
    }
    std::cout << std::endl;
    for (auto vt = volumn.rbegin(); vt != volumn.rend(); ++vt)
    {
        std::cout << *vt << " ";
    }
    std::cout << std::endl;
    /*将所有元素赋值为100*/
    volumn.assign(100);
    display(volumn);


}

int main()
{

    test01();
    system("pause");
    return 0;
}

5 5 5 5 5 5 5 5 5 5
out of bound
the container has 10 elements
1 2 3 4 5 6 7 8 9 10
10 9 8 7 6 5 4 3 2 1
10 9 8 7 6 5 4 3 2 1
100 100 100 100 100 100 100 100 100 100
请按任意键继续. . .