LINQ where vs takewhile

Question

I want to get a difference between TakeWhile & Where LINQ methods .I got the following data from MSDN .But It didn\'t make sense to me

Where

        

Answer 1

While the existing answers are correct, none of them point out why you'd want to use TakeWhile if the results would be the same: Performance. Suppose you have an ordered list with 2 billion items in it, and you want the ones that (probably 10 or 15 items) less than a given vallue. The Where clause will examine all 2 billion items, while the TakeWhile will stop as soon as it finds a value equal or greater than your supplied value