Question

在结构体里，什么时候用-> 什么时候用.

#include <iostream>
#include <string>
using namespace std;

struct Cat
{
int weight;
string name;
};

typedef Cat CAT;

int main()
{
CAT c1;
c1.weight = 5;
c1.name = "jerry";
cout << c1.name << " " << c1.weight << endl;

Cat c2;
c2.weight = 3;
c2.name = "tom";
cout << c2.name << " " << c2.weight << endl;

CAT* pc = new Cat();
pc->weight = 10;
pc->name = "kitty";
cout << pc->name << " " << pc->weight << endl;
delete pc;

CAT* pc1 = &c1;
cout << pc1->name << " " << pc1->weight << endl;

CAT* pcc2 = new Cat[2];
pcc2[0] = c1;
pcc2[1] = c2;
cout << pcc2[0].name << " " << pcc2[0].weight << endl;
cout << pcc2[1].name << " " << pcc2[1].weight << endl;
delete[] pcc2;

return 0;

}

请问：什么时候用-> 什么时候用.

Answer 1

当变量是指针的时候，访问其成员就要用 -> 否则就用.（点）

追问

但上面最后一个是指针 为何不是->

追答

你说的是pcc2[0] 这个是吧
你看你的赋值语句: pcc2[0] = c1; 他和c1是一样的，而c1是Cat对象，所以用点
pcc2是指针，所以pcc2[0].weight 也可以写作 pcc2->weight
pcc2[1].weight可以写作 (pcc2+1)->weight
这一块是指针和数组的关系，你可以去看一下相关的知识