C/C++ 指针的使用

#include<iostream>

using namespace std;

int main()

{

int *p =new int(2);

int *q = new int(3);

cout<<"before p = q"<<endl<<"address of p and value:"<<p<<" "<<*p<<endl<<"address of q and value:"<<q<<" "<<*q<<endl;

p = q;     //p没有使用它本身分配的内存而是指向q

cout<<"after p = q"<<endl<<"address of p and value:"<<p<<" "<<*p<<endl<<"address of q and value:"<<q<<" "<<*q<<endl;

delete q;     //删除后q指向的内存被释放

cout<<"after detete q (but not q=NULL)"<<endl<<"address of p and value:"<<p<<" "<<*p<<endl<<"address of q and value:"<<q<<" "<<*q<<endl;
q = NULL;

return 0;

}

运行结果如下: