1.使用eval
var parse_json_by_eval = function(str){
    return eval('('+str+')');
}
var value = 1;
var jsonstr = '{"name":"jifeng","company":"taobao","value":++value}';
var json1 = parse_json_by_eval(jsonstr);
console.log(json1);
console.log('value: '+ value);

执行结果：
{ name: 'jifeng', company: 'taobao', value: 2 }
value: 2

2.使用JSON.parse
var parse_json_by_JSON_parse = function(str){
    return JSON.parse(str);
}
value = 1;
var jsonstr = '{"name":"jifeng","company":"taobao"}';
var json2 = parse_json_by_JSON_parse(jsonstr);
console.log(json2);
console.log(value);

PHP:

$json_string = '{"id":1,"name":"xxx","email":"admin@xxx.net","interest":["wordpress","php"]} ';
$obj = json_decode($json_string);
echo $obj->name; //prints foo
echo $obj->interest[1]; //prints php 

Java:

JSONObject  dataJson = new JSONObject("{\"data\":\"json\"}");
JSONObject  response = dataJson.getJSONObject("response");
JSONArray data = response.getJSONArray("data");
JSONObject info = data.getJSONObject(0);
String province = info.getString("province");
String city = info.getString("city");
String district = info.getString("district");
String address = info.getString("address");
System.out.println(province + city + district + address);

C#:

使用开源的类库Newtonsoft.Json(下载地址http://json.codeplex.com/)。下载后加入工程就能用。通常可以使用JObject, JsonReader, JsonWriter处理。这种方式最通用，也最灵活，可以随时修改不爽的地方。
(1)使用JsonReader读Json字符串：
string jsonText =@"{""input"" : ""value"",""output"" : ""result""}";
JsonReader reader = new JsonTextReader(newStringReader(jsonText));
while (reader.Read())
{
   Console.WriteLine(reader.TokenType + "\t\t" + reader.ValueType+ "\t\t" + reader.Value);
}

(2)使用JsonWriter写字符串：
StringWriter sw = new StringWriter();
JsonWriter writer = new JsonTextWriter(sw);

writer.WriteStartObject();
writer.WritePropertyName("input");
writer.WriteValue("value");
writer.WritePropertyName("output");
writer.WriteValue("result");
writer.WriteEndObject();
writer.Flush();

string jsonText =sw.GetStringBuilder().ToString();
Console.WriteLine(jsonText);

(3)使用JObject读写字符串：
JObject jo = JObject.Parse(jsonText);
string[] values =jo.Properties().Select(item => item.Value.ToString()).ToArray();

(4)使用JsonSerializer读写对象(基于JsonWriter与JsonReader):
数组型数据
string jsonArrayText1 ="[{'a':'a1','b':'b1'},{'a':'a2','b':'b2'}]";
JArray ja =(JArray)JsonConvert.DeserializeObject(jsonArrayText1);
string ja1a =ja[1]["a"].ToString();
//或者
JObject o = (JObject)ja[1];
string oa = o["a"].ToString();
 

Python:

import json

data = json.loads('{"ID": "2", "IP":"12.12.12.12", "Port": "3000", "Sensor_Count":"1", "Control_Count": "1", "Sensors":{"Sensor_Name": "tem", "Type_Count": "1", "Types":{ "types":["temp","C"],"types":["hum","N"],}},"Controls":["LCD","Relay"] }')
print(data['ID']) # '2'
data = json.dump(data)
print(data)