{
   "name": "Мониторы 4K",
   "resolutions": [
      {
         "width": 1280,
         "height": 720
      },
      {
         "width": 1920,
         "height": 1080
      },
      {
         "width": 3840,
         "height": 2160
      }
   ]
}

cJSON *jmonitor = cJSON_CreateObject();
cJSON_AddStringToObject(jmonitor, "name", "Awesome 4K");

jresolutions = cJSON_CreateArray();
cJSON_AddItemToObject(jmonitor, "resolutions", jresolutions);

cJSON *jresolution = NULL;

for (int index = 0; index < (sizeof(resolution_numbers) / (2 * sizeof(int))); index++)
{
   jresolution = cJSON_CreateObject();
   cJSON_AddNumberToObject(jresolution, "width", resolution_numbers[index][0]);
   cJSON_AddNumberToObject(jresolution, "height", resolution_numbers[index][0]);
   cJSON_AddItemToArray(jresolutions, jresolution);
}

printf("%s\n", cJSON_Print(jmonitor));
cJSON_Delete(jmonitor);