C# 'or' operator?

Question

Is there an or operator in C#?

I want to do:

if (ActionsLogWriter.Close or ErrorDumpWriter.Close == true) {     // Do stuff here } 

But I'm not sure how I could do something like that.

Answer 1

C# supports two boolean or operators: the single bar | and the double-bar ||.

The difference is that | always checks both the left and right conditions, while || only checks the right-side condition if it's necessary (if the left side evaluates to false).

This is significant when the condition on the right-side involves processing or results in side effects. (For example, if your ErrorDumpWriter.Close method took a while to complete or changed something's state.)

Answer 2

Also worth mentioning, in C# the OR operator is short-circuiting. In your example, Close seems to be a property, but if it were a method, it's worth noting that:

if (ActionsLogWriter.Close() || ErrorDumpWriter.Close()) 

is fundamentally different from

if (ErrorDumpWriter.Close() || ActionsLogWriter.Close()) 

In C#, if the first expression returns true, the second expression will not be evaluated at all. Just be aware of this. It actually works to your advantage most of the time.