#338 – Static Readonly Fields vs. Constants

A static readonly field in a class is very similar to a constant.  Both expose a constant, static value that is associated with the class, independent of any instances of the class.

We could declare a static readonly field in a Dog class:

        public static readonly string TheDogMotto = "Man's Best Friend";

We could also declare this value as a constant:

        public const string TheDogMotto = "Man's Best Friend";

The value of a constant must be known at compile-time and specified as part of the declaration.

The value of a static readonly field is set at run-time, so it can be different from run to run.  It is specified in either the declaration or within a static constructor.

Use a readonly field for values that you won’t know until run-time or have to calculate.  Use a constant for values that are known and never change.


About Sean
Software developer in the Twin Cities area, passionate about software development and sailing.

One Response to #338 – Static Readonly Fields vs. Constants

  1. Pingback: #603 – Using Constants Can Force Recompilation « 2,000 Things You Should Know About C#

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: