Reading a json file and change it with JSON.NET

Question

JSON is really new to me. How can i use JSON.NET to add a key value pair into a already created json file?

It looks like this:

{
"data": {
    "subData1": {
        "key1":"value1",
        "key2":"value2",
        "key3":"value3"
    },
    "subdata2": {
        "key4":"value4",
        "key5":"value5",
        "key6":"value6"
    }
}
"key7":"value7",
"key8":"value8"     
}

Say for an example that i want to change it to the following:

{
"data": {
    "subData1": {
        "key1":"value1",
        "key2":"value2",
        "key3":"value3"
    },
    "subdata2": {
        "key4":"value4",
        "key5":"value5",
        "key6":"value6"
    },
    "newSubData": {
        "myKey1":"myVal1",
        "myKey2":"myVal2",
        "myKey3":"myVal3"
    }
}
"key7":"anotherValChangeByMe",
"key8":"value8"     
}

Do i need to read the whole JSON file into a dynamic, and then change / add the things i need somehow ?

Deserialize the json to your model object. Add values to object and serialize it back to json and JSON.NET is the library that actually allows this to be done very easily. — Nofel Mahmood
– Nofel Mahmood, Commented Oct 14, 2014 at 22:23

Brian Rogers · Accepted Answer · 2014-10-15 00:24:52Z

You can parse the JSON into a JObject, manipulate it via the LINQ-to-JSON API, then get the updated JSON string from the JObject.

For example:

string json = @"
{
    ""data"": {
        ""subData1"": {
            ""key1"": ""value1"",
            ""key2"": ""value2"",
            ""key3"": ""value3""
        },
        ""subdata2"": {
            ""key4"": ""value4"",
            ""key5"": ""value5"",
            ""key6"": ""value6""
        }
    },
    ""key7"": ""value7"",
    ""key8"": ""value8""
}";

JObject root = JObject.Parse(json);
JObject data = (JObject)root["data"];
JObject newSubData = new JObject();
newSubData.Add("myKey1", "myValue1");
newSubData.Add("myKey2", "myValue2");
newSubData.Add("myKey3", "myValue3");
data.Add("newSubData", newSubData);
root["key7"] = "anotherValChangeByMe";

Console.WriteLine(root.ToString());

Output:

{
  "data": {
    "subData1": {
      "key1": "value1",
      "key2": "value2",
      "key3": "value3"
    },
    "subdata2": {
      "key4": "value4",
      "key5": "value5",
      "key6": "value6"
    },
    "newSubData": {
      "myKey1": "myValue1",
      "myKey2": "myValue2",
      "myKey3": "myValue3"
    }
  },
  "key7": "anotherValChangeByMe",
  "key8": "value8"
}

Cam Bruce · Accepted Answer · 2014-10-14 22:31:13Z

1

JSON is ultimately just a string. If you are working on the server side, then unless you want to try to parse out the JSON yourself, the easiest way is to use JSON.NET to deserialize it back into it's native object model. Of course, you can also do this on the client side with JSON.parse(), and add the value there, too.

answered Oct 14, 2014 at 22:31

Cam Bruce

5,68924 silver badges37 bronze badges

Collectives™ on Stack Overflow

Reading a json file and change it with JSON.NET

2 Answers 2

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Related