C# 4.0 Optional Parameters

Switching back and forth from C#, PHP and Javascript always lead me to mixing up the features available for each language. e.g. I was expecting there is Optional/Default Parameters in C# just like PHP, but it doesn't have it until C#4.0 (include in .Net 3.5). Moreover, it has the named parameters features which help to clear some ambiguous case! Here is a short tutorial for that feature C# 4.0 Optional Parameters