cjson解析下面的数据

假设需要解析的JSON数据如下：

{
    "name": "John",
    "age": 30,
    "city": "New York",
    "hobbies": ["reading", "traveling", "swimming"],
    "education": {
        "degree": "Master",
        "major": "Computer Science"
    }
}

使用cJSON库进行解析的示例代码如下：

#include <stdio.h>
#include <stdlib.h>
#include "cJSON.h"

int main() {
    char *json_str = "{\"name\":\"John\",\"age\":30,\"city\":\"New York\",\"hobbies\":[\"reading\",\"traveling\",\"swimming\"],\"education\":{\"degree\":\"Master\",\"major\":\"Computer Science\"}}";

    cJSON *root = cJSON_Parse(json_str);
    if (root == NULL) {
        printf("Error before: [%s]\n", cJSON_GetErrorPtr());
        return 1;
    }

    cJSON *name = cJSON_GetObjectItemCaseSensitive(root, "name");
    if (cJSON_IsString(name) && (name->valuestring != NULL)) {
        printf("Name: %s\n", name->valuestring);
    }

    cJSON *age = cJSON_GetObjectItemCaseSensitive(root, "age");
    if (cJSON_IsNumber(age)) {
        printf("Age: %d\n", age->valueint);
    }

    cJSON *city = cJSON_GetObjectItemCaseSensitive(root, "city");
    if (cJSON_IsString(city) && (city->valuestring != NULL)) {
        printf("City: %s\n", city->valuestring);
    }

    cJSON *hobbies = cJSON_GetObjectItemCaseSensitive(root, "hobbies");
    if (cJSON_IsArray(hobbies)) {
        int i, size = cJSON_GetArraySize(hobbies);
        printf("Hobbies:\n");
        for (i = 0; i < size; i++) {
            cJSON *item = cJSON_GetArrayItem(hobbies, i);
            if (cJSON_IsString(item) && (item->valuestring != NULL)) {
                printf("  %s\n", item->valuestring);
            }
        }
    }

    cJSON *education = cJSON_GetObjectItemCaseSensitive(root, "education");
    if (cJSON_IsObject(education)) {
        cJSON *degree = cJSON_GetObjectItemCaseSensitive(education, "degree");
        if (cJSON_IsString(degree) && (degree->valuestring != NULL)) {
            printf("Education - Degree: %s\n", degree->valuestring);
        }
        cJSON *major = cJSON_GetObjectItemCaseSensitive(education, "major");
        if (cJSON_IsString(major) && (major->valuestring != NULL)) {
            printf("Education - Major: %s\n", major->valuestring);
        }
    }

    cJSON_Delete(root);

    return 0;
}

运行结果：

Name: John
Age: 30
City: New York
Hobbies:
  reading
  traveling
  swimming
Education - Degree: Master
Education - Major: Computer Science

解析过程中，先使用cJSON_Parse函数将JSON字符串解析成一个cJSON对象（即root）。然后，使用cJSON_GetObjectItemCaseSensitive函数分别获取其中的各个成员对象，并使用不同的cJSON类型判断函数（如cJSON_IsString、cJSON_IsNumber、cJSON_IsArray等）判断其类型。最后，使用各自的value获取成员对象的值。最后，使用cJSON_Delete函数释放cJSON对象。