c++ - PointList &L 与 PointList L 的区别？

Question

最近看老师的程序
PointList 就是一个点列表结构体

struct Point
{
    float x, y;
};

struct PointList
{
    int size;
    int cur;
    struct Point points[10];
};

为什么有时候在函数中使用 PointList L 做参数，有时候使用 PointList &L，两者有什么区别呢？

Answer 1

This is not C but C++, PointList &L, I am used to writing it as PointList& L, which declares a reference type. If the function parameter is not a reference type, a copy will be made. If it is a reference type, the original structure value will be passed.

Answer 2

In short, PointList L passes the value and PointList &L passes the address.

For non-primitive types, please always use PointList &L as formal parameters. If you do not want to change the actual parameters, please use const PointList &L.