C語言可以通過結構體的方式來形成json格式的數據，具體的實現過程可以通過以下代碼進行演示：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <limits.h>
#define BUFFER_SIZE 100
typedef struct {
char *key;
char *value;
} KeyValue;
typedef struct {
char *type;
char *name;
int age;
char *email;
KeyValue *metadata;
int metadataCount;
} Person;
int main(int argc, char *argv[]) {
char buffer[BUFFER_SIZE];
Person person;
KeyValue metadata[2];
// Initialize metadata
metadata[0].key = "hobby";
metadata[0].value = "reading";
metadata[1].key = "occupation";
metadata[1].value = "developer";
// Initialize person
person.type = "person";
person.name = "John Doe";
person.age = 30;
person.email = "john.doe@example.com";
person.metadata = metadata;
person.metadataCount = 2;
// Serialize person as json
snprintf(buffer, BUFFER_SIZE, "{"
"\"type\":\"%s\","
"\"name\":\"%s\","
"\"age\":%d,"
"\"email\":\"%s\","
"\"metadata\":["
"{\"key\":\"%s\",\"value\":\"%s\"},"
"{\"key\":\"%s\",\"value\":\"%s\"}"
"]"
"}",
person.type,
person.name,
person.age,
person.email,
person.metadata[0].key,
person.metadata[0].value,
person.metadata[1].key,
person.metadata[1].value);
printf("%s\n", buffer);
return 0;
}

以上代碼演示了如何通過結構體的方式來存儲json格式的數據，并將其序列化為字符串輸出。這種方式可以讓我們在C語言中方便地處理json格式的數據，以便應用于各種場景。