how to force WebAPI in MVC4 to render null strings as empty in json result

Question

How to render null string properties as empty strings in ASP.NET MVC4 Web API v.1 in json result? WebAPI renders them as ``` "myproperty": null ``` how to render this as ``` "myproperty": "" ``` controller is ``` public class Customer { public string myproperty { get; set; } } public class CustomersController : ApiController { public HttpResponseMessage Get() { var cust = new Customer(); return Request.CreateResponse(HttpStatusCode.OK, new { customers = cust.ToArray() }); } } ``` object are nested and contain lot of string properties. Setting them all to empty strings in constructor seems ugly. API caller needs empty strings or 0 for decimals, it does not like null constant in any value.

Accepted Answer

you can decorate your properties like this :

```
[JsonProperty(DefaultValueHandling = DefaultValueHandling.Populate)]
[DefaultValue("")]
public string myproperty{ get; set; }
```

Note that you can set the default value handling to populate in a global config like this:

```
GlobalConfiguration
.Configuration
.Formatters
.JsonFormatter
.SerializerSettings
.DefaultValueHandling = Newtonsoft.Json.DefaultValueHandling.Populate;
```

So, you don't need to decorate it to every property. You will only need to use the `DefaultValue`.

how to force WebAPI in MVC4 to render null strings as empty in json result

Solution

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