Replace a variable in a JSON string

What you're trying to do is replace a token in your string with another string. If your JSON file looks like this:

{
    "NPCIDxxGreeting":{
        "text": "Yo, $name, what's up?"
    }
}

You can load this string and then replace $name with the playerName variable.

If you're using JSON.NET, you can parse the JSON file like this:

dynamic dialogue = JObject.Parse(json);

Then, pull the string out and replace the $name token:

var greeting = dialogue["NPCIDxxGreeting"].text.ToString();
var playerGreeting = greeting.Replace("$name", playerName);

Here's a fiddle that demonstrates it: Replace variable in JSON

.NET supports Json converting. So basically you read in the file contents and just parse the JSON information.

Example

public class Stats
{
    public int attack;
    public string playerName;
    public float speed;
    ......
}
public static List<string>GetJson()
{
    using (StreamReader r = new StreamReader("file.json"))
    {
        string json = r.ReadToEnd();
        List<Stats> stats = JsonConvert.DeserializeObject<List<Stats>>(json);
        return stats ; 
    }
}