Validate a string to be json or not in asp.net

6
votes

is there any way to validate a string to be json or not ? other than try/catch .

I'm using ServiceStack Json Serializer and couldn't find a method related to validation .

3
asp.netjsonservicestack
possible duplicate of Check JSON and XML is valid? c# – Dennis Traub
that solution uses try/catch . I'm looking for method like TryParse that we have for int,date,... . just to check if string contains a valid json structure or not – mohsen dorparasti
Possible duplicate of How to make sure that string is Valid JSON using JSON.NET – Michael Freidgeim

3 Answers

16
votes

Probably the quickest and dirtiest way is to check if the string starts with '{':

public static bool IsJson(string input){ 
    input = input.Trim(); 
    return input.StartsWith("{") && input.EndsWith("}")  
           || input.StartsWith("[") && input.EndsWith("]"); 
}

Another option is that you could try using the JavascriptSerializer class:

JavaScriptSerializer ser = new JavaScriptSerializer(); 
SomeJSONClass = ser.Deserialize<SomeJSONClass >(json);

Or you could have a look at JSON.NET:

0
votes

You can find a couple of regular expressions to validate JSON over here: Regex to validate JSON

It's written in PHP but should be adaptable to C#.

0
votes

A working code snippet

public bool isValidJSON(String json)
{
    try
    {
        JToken token = JObject.Parse(json);
        return true;
    }
    catch (Exception ex)
    {
        return false;
    }
}

Source