有什么方法可以在 C 中循环遍历具有不同类型元素的结构? [英] Is there any way to loop through a struct with elements of different types in C?

问题描述

我的结构有点像这样

typedef struct {
  type1 thing;
  type2 thing2;
  ...
  typeN thingN;
} my_struct 

如何在 while 或 for 等循环中枚举 struct childs?

how to enumerate struct childrens in a loop such as while, or for?

推荐答案

我不确定您想要实现什么，但是您可以使用 X-Macros 并让预处理器对结构的所有字段进行迭代:

I'm not sure what you want to achieve, but you can use X-Macros and have the preprocessor doing the iteration over all the fields of a structure:

//--- first describe the structure, the fields, their types and how to print them
#define X_FIELDS 
    X(int, field1, "%d") 
    X(int, field2, "%d") 
    X(char, field3, "%c") 
    X(char *, field4, "%s")

//--- define the structure, the X macro will be expanded once per field
typedef struct {
#define X(type, name, format) type name;
    X_FIELDS
#undef X
} mystruct;

void iterate(mystruct *aStruct)
{
//--- "iterate" over all the fields of the structure
#define X(type, name, format) 
         printf("mystruct.%s is "format"
", #name, aStruct->name);
X_FIELDS
#undef X
}

//--- demonstrate
int main(int ac, char**av)
{
    mystruct a = { 0, 1, 'a', "hello"};
    iterate(&a);
    return 0;
}

这将打印:

mystruct.field1 is 0
mystruct.field2 is 1
mystruct.field3 is a
mystruct.field4 is hello

你也可以在X_FIELDS中添加要调用的函数名...

You can also add the name of the function to be invoked in the X_FIELDS...

这篇关于有什么方法可以在 C 中循环遍历具有不同类型元素的结构?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！