class T{public: T() { cout<<"T()"<<endl; }};
int* p = new int(); //初始化为0 int* q = new int; //不初始化 cout<<*p<<endl; cout<<*q<<endl;
T* t = new T;//调用默认构造函数 t = new T();//调用默认构造函数，这两者没有区别
