.Net Tips – Getting the default value of a type outside of generics

Yan Cui

I help clients go faster for less using serverless technologies.

This article is brought to you by

The real-time data platform that empowers developers to build innovative products faster and more reliably than ever before.

Learn more

To get the default value of a type, you’ve probably used the default keyword in .Net already:

   1: var defaultInt = default(int);        // 0

   2: var defaultObj = default(string);     // null

However, the use of the default keyword requires a type name to be specified at compile time, so you won’t be able to use it on a type which you discover at runtime. Instead, you will need to do something along the line of:

   1: public object GetDefaultValue(Type type)

   2: {

   3:     // Handle value types and reference types differently

   4:     if (type.IsValueType)

   5:     {

   6:         return Activator.CreateInstance(type);

   7:     }

   8:     else

   9:     {

  10:         return null;

  11:     }

  12: }

It’ll yield the same result as using the default keyword:

   1: var defaultInt = GetDefaultValue(typeof(int));        // 0

   2: var defaultObj = GetDefaultValue(typeof(string));     // null

Whenever you’re ready, here are 4 ways I can help you:

  1. Production-Ready Serverless: Join 20+ AWS Heroes & Community Builders and 1000+ other students in levelling up your serverless game. This is your one-stop shop for quickly levelling up your serverless skills.
  2. Do you want to know how to test serverless architectures with a fast dev & test loop? Check out my latest course, Testing Serverless Architectures and learn the smart way to test serverless.
  3. I help clients launch product ideas, improve their development processes and upskill their teams. If you’d like to work together, then let’s get in touch.
  4. Join my community on Discord, ask questions, and join the discussion on all things AWS and Serverless.

Leave a Comment

Your email address will not be published. Required fields are marked *