Do LINQ queries have a lot of overhead?

Question

Are simple LINQ queries on an IEnumerable lightweight or heavyweight? How do they compare to writing for or foreach loops by

Answer 1

According to LINQ In Action (pg.198):

"LINQ does not come for free. LINQ queries cause additional work, object creations, and pressure on the garbage collector. The additional cost of using LINQ can vary a lot depending on the query. It can be as low as 5 percent, but can sometimes be around 500 percent."