How to use a variable name when creating a json string

Question

I am doing something like this

string tag_prop = "foo_bar";
string guid = "ABC";
string str = JsonConvert.SerializeObject(new { tags = new { tag_prop = guid } });

I noticed that I get the following JSON string.

{
tags : {
   tag_prop : "ABC"
        }
}

My question is how can I tell the above statement that tag_prop is actually a variable and get this

{
    tags : {
       foo_bar: "ABC"
            }
    }

What's the expected output? JSON can't contain variable references. — madreflection
– madreflection, Commented Aug 9, 2019 at 21:59
No, you can't use the value of a variable as the name of a property in an anonymous type declaration. — Jonathon Chase
– Jonathon Chase, Commented Aug 9, 2019 at 22:08

madreflection · Accepted Answer · 2019-08-09 22:24:40Z

1

One way is to make tags a dictionary and use tag_prop as the parameter to the indexer. The following will give you the output you expect (with proper quoting of properties). If your situation is more complicated, you may have to adapt it futher.

string tag_prop = "foo_bar";
string guid = "ABC";
string str = JsonConvert.SerializeObject(
    new
    {
        tags = new Dictionary<string, string>
        {
            [tag_prop] = guid
        }
    }, Formatting.Indented);

The output is:

{
  "tags": {
    "foo_bar": "ABC"
  }
}

edited Aug 9, 2019 at 22:24

answered Aug 9, 2019 at 22:09

madreflection

5,0273 gold badges26 silver badges34 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

AlmaniaM · Accepted Answer · 2019-08-09 22:15:31Z

0

You could do this:

public static ExpandoObject CreateExpandoObject(string prop, object val)
{
    dynamic expando = new ExpandoObject();
    expando = AddPropertyWithValue(expando, prop, val is null ? "" : val);
    return expando;
}

public void YourMethod() {
    string tag_prop = "foo_bar";
    string guid = "ABC";
    var dynamicPropertyObject = CreateExpandoObject(tag_prop, guid);
    string str = JsonConvert.SerializeObject(new { tags = dynamicPropertyObject });
}

answered Aug 9, 2019 at 22:15

AlmaniaM

2152 silver badges5 bronze badges

Collectives™ on Stack Overflow

How to use a variable name when creating a json string

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related