顺序栈-构造函数与析构函数

C++实现顺序栈

#include 
using namespace std;
class SeqStack
{
public:
    SeqStack(int size = 10)
    {
        cout<<this<<" SeqStack() " <<endl;
        _pstack=new int[size];
        _top=-1;
        _size=size;
    }
    ~SeqStack(){
        cout<<this <<" ~SeqStack() "<<endl;
        delete [] _pstack;
        _pstack = nullptr;
    }
    void push(int val)
    {
        if(full())
            resize();
        _pstack[++_top]=val;
    }
    void pop()
    {
        if(empty()) return;
        --_top;
    }
    int top()
    {
        return _pstack[_top];
    }
    bool empty(){
        return _top == -1;
    }
    bool full(){
        return _top == _size -1;
    }

private:
    int *_pstack;
    int _top;
    int _size;

    void resize()
    {
        int *ptmp = new int[_size*2];
        for(int i=0;i<_size;i++)
        {
            ptmp[i]=_pstack[i];
        }
        delete [] _pstack;
        _pstack = ptmp;
        _size*=2;
    }
};
SeqStack gs;
int main() {
//    SeqStack *ps =new SeqStack(60);
//    ps->push(70);
//    ps->push(80);
//    ps->pop();
//    cout<<"s.top():   "<top()<
//    delete ps;

    SeqStack s;
    for(int i=0;i<10;i++)
    {
        s.push(rand()%100);
    }
    while(!s.empty())
    {
        s.pop();
    }

    SeqStack s1(50);
    s1.push(30);

    return 0;
}

此处注意
1.先构造后析构
2.全局类再程序结束后析构