Let in LINQ 🔮

A let clause introduces a new range variable with a value that can be based on other range variables.

❌ Sorting by the lengths of usernames without let clause :

var query = 
    from user in SampleData.AllUsers
    orderby user.Name.Length
    select user.Name;

foreach (var name in query)
      Console.WriteLine("{0}: {1}", name.Length, name);

✅ Using a let clause to remove redundant calculations :

var query = 
   from user in SampleData.AllUsers
   let length = user.Name.Length
   order by length
   select new 
   {
       Name= user.Name,
       Length = length
   };

foreach (var entry in query)
    Console.WriteLine("{0}:{1}",entry.Length, entry.Name);

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#LINQ #Query
@ProgrammingTip