1如果不使用new，则在函数结束时内存被回收，指针变成野指针
#include <iostream> using namespace std; struct Node { int val; Node *next; Node(int v=0,Node * n=NULL){ val=v; next=n; } }; Node * head; void fun(){ Node t(1); head=&t; cout<<"head"<<head->val<<" "<<head->next<<endl; } int main(){ fun(); cout<<"head"<<head->val<<" "<<head->next<<endl; return 0; }
执行完成，耗时：0 ms head1 0 head54732392 0x7fc624c80649
2如果使用new，则必须使用delete才能回收内存
#include <iostream> using namespace std; struct Node { int val; Node *next; Node(int v=0,Node * n=NULL){ val=v; next=n; } }; Node * head; void fun(){ head=new Node(1); cout<<"head"<<head->val<<" "<<head->next<<endl; } int main(){ fun(); cout<<"head"<<head->val<<" "<<head->next<<endl; delete head; return 0; }
执行完成，耗时：4 ms head1 0 head1 0
原文：https://www.cnblogs.com/LPworld/p/12902045.html