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Super Lambda Bananas

I’m a big generic collection user and I can’t express how much the C# 3 Linq expressions have improved my coding experience, especially in the form of lambda syntax. I used to spend a lot of time trying to bend predicates to my will in order to pull the good stuff out of my collections, and some of the new expressions make this a thing of the past.

Some of the expressions do need a bit of extra thought to understand what is going on though. For example, what is the difference between .Where, .TakeWhile and .SkipWhile? They all return a subset of your collection, but what exactly do you get? Let’s investigate!

So say we start with this:

string[] names = {"dave", "dee", "dozy", "beaky",
"mick", "titch", "darius"};

names.Where(name => name.StartsWith("d"));

 .Where will return “dave”, “dee”, “dozy” and “darius”, matching everything that starts with ‘d’. TakeWhile and SkipWhile are different though, working on your sequence only until a specified condition is deemed false. So…..

names.TakeWhile(name => name.StartsWith("d"));

will return “dave”, “dee” and “dozy”: the search is called off when StartsWith(”d”) becomes false. Conversely

names.SkipWhile(name => name.StartsWith("d"));

 

will get you “beaky”, “mick”, “titch” and “darius”, skipping the items in the sequence until StartsWith(”d”) becomes false.

Try doing that with predicates!