Great job — we just covered a lot of LINQ! Here’s a recap:

  • LINQ is a set of language and framework features for writing structured, type-safe queries over local object collections and remote data sources.
  • Use LINQ by referencing the System.Linq namespace in your file.
  • When a LINQ query returns a sequence of elements its type is IEnumerable<T>. That means it works with foreach loops and its length is accessible with Count().
  • Store a query’s result in a variable of type var. var is an implicit type, meaning it gets all of the benefits of type-checking without our specifying the actual type.
  • LINQ queries can be written in method syntax or query syntax.
  • We prefer method syntax for single operations and query syntax for most everything else.
  • The Where operator is used to select certain elements from a sequence.
  • The Select operator determines what is returned for each element in the sequence.
  • The from operator declares a range variable that is used to traverse the sequence.
  • LINQ can be used on arrays and lists, among other datatypes.

If you’re curious or want more practice, here are some additional resources:



There are a few bugs in this code! Fix each one before moving on.

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