#include <iostream>

using namespace std;

char arr[10]="12345678";
void show(int i)
{
    if(i>=10)
    {
        throw int(2);
    }
    cout << arr[i] <<endl;
}
int main()
{
    int i;
    cin >> i;
    try {
        show(i);
    } catch (int) {
        cout << "越界" <<endl;
    }
    return 0;
}

使用模板类，实现顺序栈：

#include <iostream>

using namespace std;

template <typename T>
class stack{
    T top;
    T data[5]={};
public:
    stack():top(4)
    {}
    void ru(T a);
    void chu();
    void show()
    {
        for(int i=0;i<5;i++)
        {
            cout << data[i] <<endl;
        }
    }
};

template <typename T>
void stack<T>::ru(T a)
{
    data[top]=a;
    top--;
}

template <typename T>
void stack<T>::chu()
{
    top++;
    data[top]=0;
}

int main()
{
    stack <int>s1;
    s1.show();
    cout << "---------"<<endl;
    s1.ru(99);
    s1.ru(88);
    s1.show();
    cout << "---------"<<endl;
    s1.chu();
    s1.show();
    cout << "---------"<<endl;
    s1.ru(66);
    s1.show();
    return 0;
}