cJSON库的下载

git链接：https://github.com/moonright/cJSON

cJSON库的引用

该库非常简单，下载解压后如下图，正常使用时只需要cJSON.h和cJSON.c两个文件，将两个文件放入到项目中，引用cJSON.h头文件即可。

示例

#include <iostream>
#include <string.h>
#include <stdio.h>
#include<time.h>
#include "cJSON-master/cJSON.h"

using namespace std;

//创建json字符串
void creat_cjsonstr(char *cjsonstr, int max_len)
{
    char *tmp_str;
    cJSON *root = NULL;
    cJSON *root1 = NULL;
    cJSON *array = NULL;
    cJSON *mother = NULL;
    cJSON *father = NULL;


    //创建一个cJSON对象
    root = cJSON_CreateObject();
    //添加一个字符串
    cJSON_AddStringToObject(root, "name", "Dave");
    //添加一个数字
    cJSON_AddNumberToObject(root, "age", 24);

    //创建嵌套cJSON对象
    root1 = cJSON_CreateObject();
    cJSON_AddItemToObject(root, "other", root1);
    //root1 = cJSON_AddObjectToObject(root, "other");
    //创建cJSON数组
    array = cJSON_CreateArray();
    cJSON_AddItemToObject(root1, "relative", array);

    //向数组中添加无名对象
    father = cJSON_CreateObject();
    cJSON_AddItemToArray(array, father);
    cJSON_AddStringToObject(father, "name", "Jonh");
    cJSON_AddNumberToObject(father, "age", 46);

    mother = cJSON_CreateObject();
    cJSON_AddItemToArray(array, mother);
    cJSON_AddStringToObject(mother, "name", "Lisa");
    cJSON_AddNumberToObject(mother, "age", 46);



    //添加一个空的对象，并返回节点的名称
    cJSON *object = cJSON_AddObjectToObject(root1, "object");
    cJSON *arrays = cJSON_AddArrayToObject(root1, "array");

    // 打印 JSON 字符串
    tmp_str = cJSON_Print(root);
    //printf("%s\n", tmp_str);

    //拷贝数据
    memcpy(cjsonstr, tmp_str, strlen(tmp_str));

    // 清理内存
    cJSON_free(tmp_str);
    cJSON_Delete(root);
}

//解码json字符串
void parse_cjsonstr(char *str)
{
    cJSON *root = NULL;
    cJSON *other = NULL;
    cJSON *relative = NULL;
    cJSON *element = NULL;

    root = cJSON_Parse(str);
    other = cJSON_GetObjectItemCaseSensitive(root, "other");
    relative = cJSON_GetObjectItemCaseSensitive(other, "relative");

    printf("root_name: %s\n", cJSON_GetStringValue(cJSON_GetObjectItemCaseSensitive(root, "name")));

    cJSON_ArrayForEach(element, relative)
    {
        printf("name: %s\n", cJSON_GetStringValue(cJSON_GetObjectItemCaseSensitive(element, "name")));
        printf("age: %d\n", (int)cJSON_GetNumberValue(cJSON_GetObjectItemCaseSensitive(element, "age")));
    }

    cJSON_Delete(root);
}

int main(int argc, char *argv[])
{
    char str[800] = {0};
    creat_cjsonstr(str, 800);
    printf("%s\n", str);
    parse_cjsonstr(str);

        return 0;
}
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