CJSON实例详解

 1 #include <stdio.h>
 2 #include "cJSON.h"
 3 
 4 int main()
 5 {
 6     cJSON * pJsonRoot = NULL;
 7 
 8     pJsonRoot = cJSON_CreateObject();
 9     if(NULL == pJsonRoot)
10     {
11         //error happend here
12         return 0;
13     }
14     cJSON_AddStringToObject(pJsonRoot, "hello", "hello world");
15     cJSON_AddNumberToObject(pJsonRoot, "number", 10010);
16     cJSON_AddBoolToObject(pJsonRoot, "bool", 1);
17     cJSON * pSubJson = NULL;
18     pSubJson = cJSON_CreateObject();
19     if(NULL == pSubJson)
20     {
21         // create object faild, exit
22         cJSON_Delete(pJsonRoot);
23         return 0;
24     }
25     cJSON_AddStringToObject(pSubJson, "subjsonobj", "a sub json string");
26     cJSON_AddItemToObject(pJsonRoot, "subobj", pSubJson);
27 
28     char * p = cJSON_Print(pJsonRoot);
29     if(NULL == p)
30     {
31         //convert json list to string faild, exit
32         //because sub json pSubJson han been add to pJsonRoot, so just delete pJsonRoot, if you also delete pSubJson, it will coredump, and error is : double free
33         cJSON_Delete(pJsonRoot);
34         return 0;
35     }
36     printf("%s\n", p);
37 
38     return 0;
39 }

1 {
2     "hello":    "hello world",
3     "number":    10010,
4     "bool":    true,
5     "subobj":    {
6         "subjsonobj":    "a sub json string"
7     }
8 }