c++中傳遞指標的一種方法

#include<iostream>using namespace std;struct A{int  a;int  b;char c;};void f(struct A *&p, int a, int b, char c){p = new struct A;if (!p){return;}else{p->a = a;p->b = b;p->c = c;}}int main(){struct A *p = NULL;f(p, 1, 2, 48);cout<<p->a<<endl;cout<<p->b<<endl;cout<<p->c<<endl;return 0;}

相當於傳遞指標的引用

 

如果寫成下面的情況是錯誤的

#include<iostream>using namespace std;struct A{int  a;int  b;char c;};void f(struct A *p, int a, int b, char c)//*p應該為*&p{p = new struct A;if (!p){return;}else{p->a = a;p->b = b;p->c = c;}}int main(){struct A *p = NULL;f(p, 1, 2, 48);cout<<p->a<<endl;cout<<p->b<<endl;cout<<p->c<<endl;return 0;}