Should You Use Write-Only Properties?

I have just started a new job using a language I had never used before. I have been spending time reading up on the syntax. Whilst looking at a great document comparing VB.NET and C# which can be found here. It is here that I spotted the syntax for write-only properties.

Like all competent developers I had heard of and regularly use read-only properties, but I had never heard of or even considered write-only properties. I suppose I knew it was syntactically possible, but I had never come across a situation where I would need to use them.

I decided to do some research on write-only properties and found an ongoing debate surrounding them. One side of the argument is that they are wrong, and that a method should be used to set the value rather than a property. The other is that write-only properties should be used.

Microsoft has released design guidelines to support one side of the debate which states the following:
Do not provide set-only properties.
If the property getter cannot be provided, use a method to implement the functionality instead. The method name should begin with Set followed by what would have been the property name...
Further design guidelines around properties can be found here and here

Before the research I thought the debate was just about how the syntax looked. After the research my opinion has changed and I now believe the guidelines make an excellent point. A read-only property is used to encapsulate the data from the rest of the code, but a write-only property does not provide you with the same benefit. The .NET framework also uses methods to set values if there is not going to be a getter. Therefore, personally I believe that for consistency we should do the same.

If you enjoyed this post follow me on twitter (@agilemooney) for news of future posts.

Join the ConversationLeave a reply