How to initialize an object from a string containing key value pairs in C#

Question

The object has 139 fields; the string initializer may have some or all of these fields. It is formatted like this: "FirstName":"Bart","LastName":"Simpson","Company":"Fat Tony's","Address":"55 Maple Drive" etc. I could just look for the fields like this:

if (initializerString.contains("FirstName:") 
   FirstName="get the next series of chars until the ", or end of string

and so forth. But is there a more compact way to do this?

I am assuming you are not using JSON.NET. If this the case, then you can try it. (http://stackoverflow.com/questions/6620165/how-to-parse-json-in-c) — Farhad Jabiyev, Mar 09 '15 at 14:48
@Ron - your "string initializer" looks very much like JSON however — James Thorpe, Mar 09 '15 at 14:49
No, I mean the structure in your string is **Json** strcuture. And you can easily parse this with the help of JSON.NET library. — Farhad Jabiyev, Mar 09 '15 at 14:49
I hadn't thought about using JSON. I'll take a look at this. Very nice. — Ron, Mar 09 '15 at 14:52
So I would do something like this: var dict = JsonConvert.DeserializeObject>(json); where item is the class I'm deserializing into? — Ron, Mar 09 '15 at 15:05

score 1 · Accepted Answer · answered Mar 09 '15 at 15:13

Seeing as your format is incredibly similar to JSON (except for the lack of braces, actually), as people commented you'll fare better by using JSON.NET.

If you have complete control over this string, just transform it into a json and deserialize it:

JsonConvert.DeserializeObject<YourClass>(yourString);

It will automatically set the correct properties while deserializing your data.

In case you don't have control of this format, and you need to parse it anyway, just put up the braces and you're good:

JsonConvert.DeserializeObject<YourClass>("{" + yourString + "}");

And if you don't have a specific class for this, you can also replace YourClass for a Dictionary<string,object>

You'll find this library as Newtonsoft.Json, and I believe it's the most popular library for dealing with JSON data.

I've made a working example so you can see it in action (note that I kept your string format, but please try to use straight json):

using System;
using System.Linq;
using System.Collections.Generic;
using Newtonsoft.Json;

public class Program
{
    public class Information
    {
        public string FirstName{get;set;}
        public string LastName{get;set;}
        public string Company{get;set;}
        public string Address{get;set;}
    }

    public static void Main()
    {
        string myObject =  "\"FirstName\":\"Bart\",\"LastName\":\"Simpson\",\"Company\":\"Fat Tony's\",\"Address\":\"55 Maple Drive\"";
        var converted = JsonConvert.DeserializeObject<Dictionary<string, object>>("{"+myObject+"}");
        var converted2 = JsonConvert.DeserializeObject<Information>("{"+myObject+"}");
        Console.WriteLine(String.Join("\n", converted.Select(c=> c.Key + ": " + c.Value)));
        Console.WriteLine(converted2.FirstName);
    }
}

And here's a bonus fiddle:

https://dotnetfiddle.net/fudUYZ

score 0 · Answer 2 · answered Mar 09 '15 at 14:53

0

Using regex you could do:

 string firstName = Regex.Match(yourstring,@"(?<=""FirstName"":"").*?(?="")").Value;

However this really looks like a json string and there are easier ways to get your data.

answered Mar 09 '15 at 14:53

Florian Schmidinger

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score 0 · Answer 3 · answered Mar 09 '15 at 14:54

You could create a Dictionary<string,object> dict in which there is the name of the property and the property.

You can then split the string,

//Remove the "
initializerString = initializerString.Replace('"', '');
//Split by ,
var tmp = initializerString.Split(",");

//Foreach pair key/value split by :
foreach( var x in tmp){
    var tmp2=x.Split(":");

    //Assign the value to the property in the Dictionary
    dict[tmp2[0]]=tmp2[1];
}

Warning. Since I don't actually know what you're using this code for, this is more of a general idea than working code.

How to initialize an object from a string containing key value pairs in C#

3 Answers3