C數據生成JSON文件

JSON（JavaScript Object Notation）是一種輕量級的數據交換格式，常用于Web應用程序中的數據傳輸。

C語言是一種高效且廣泛使用的編程語言，可以用它來生成JSON格式的數據文件。

下面介紹一個使用C語言來生成JSON文件的示例程序：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_JSON_DATA 100
int main(int argc, char *argv[])
{
// 定義需要轉換為JSON數據的C結構體
struct person {
char *name;
int age;
char *address;
} p[] = {
{"Alice", 23, "New York"},
{"Bob", 28, "Los Angeles"},
{"Cathy", 35, "Chicago"},
{"David", 40, "San Francisco"},
{NULL, 0, NULL} // 結束標志
};
char json_data[MAX_JSON_DATA];
int offset = 0;
// 開始創建JSON數據格式的字符串
offset += sprintf(json_data + offset, "{\n");
offset += sprintf(json_data + offset, "    \"persons\": [\n");
struct person *p_item = p;
while (p_item->name != NULL) {
offset += sprintf(json_data + offset, "        {\n");
offset += sprintf(json_data + offset, "            \"name\": \"%s\",\n", p_item->name);
offset += sprintf(json_data + offset, "            \"age\": %d,\n", p_item->age);
offset += sprintf(json_data + offset, "            \"address\": \"%s\"\n", p_item->address);
offset += sprintf(json_data + offset, "        },\n");
p_item++;
}
offset -= 2; // 刪除最后一個逗號和回車
offset += sprintf(json_data + offset, "\n    ]\n}");
printf("JSON data:\n%s\n", json_data);
// 將JSON數據寫入文件
FILE *fp;
fp = fopen("sample.json", "w");
if (fp == NULL) {
printf("Failed to open file sample.json\n");
exit(1);
}
fputs(json_data, fp);
fclose(fp);
return 0;
}

運行上述程序后，在當前目錄下會生成一個sample.json文件，內容如下：

{
"persons": [
{
"name": "Alice",
"age": 23,
"address": "New York"
},
{
"name": "Bob",
"age": 28,
"address": "Los Angeles"
},
{
"name": "Cathy",
"age": 35,
"address": "Chicago"
},
{
"name": "David",
"age": 40,
"address": "San Francisco"
}
]
}