如何使用指向struct字段的指针？ [英] How to intilize a pointer to a struct field ?

问题描述

如何使用指向结构字段的指针



我尝试过：

how to intilize a pointer to a struct field

What I have tried:

typedef struct SVisitor
{
  char **room_name;
} Visitor;

typedef struct SChallengeRoom
{
   char *name;
} ChallengeRoom;
// i want to chane room_name in the first struct to name in the second sruct 
//i did something like this 
visitor_enter_room(ChallengeRoom *room, Visitor *visitor){
visitor->room_name=room->name
}

推荐答案

initizialation的主要状态应该是指针应为null。如果你需要一些内存，你必须分配所需的内存。



最佳做法是为每个结构分配自己的内存。

The primary state of initizialation should of a pointer should be null. If you need some memory than you must allocate the needed memory.

Best practise is to allocated own memory for every struct.

visitor_enter_room(ChallengeRoom *room, Visitor *visitor) {
visitor->room_name = malloc( strlen(room->name) + 1 );//allocate memory
strcpy( visitor->room_name,room->name); // copy string
}

如果你已经完成了那个记忆你必须使用免费清理!!!

提示：你也可以使用strdup和free。

Google了解更多细节和示例代码。

If you are done with that memory you must use free to cleanup!!!
Tip: you can also work with strdup and free.
Google for further details and sample code.

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