Code equivalent to the 'let' keyword in chained LINQ extension method calls

Solution 1:

Let doesn't have its own operation; it piggy-backs off of Select. You can see this if you use "reflector" to pull apart an existing dll.

it will be something like:

var result = names
        .Select(animalName => new { nameLength = animalName.Length, animalName})
        .Where(x=>x.nameLength > 3)
        .OrderBy(x=>x.nameLength)
        .Select(x=>x.animalName);

Solution 2:

There's a good article here

Essentially let creates an anonymous tuple. It's equivalent to:

var result = names.Select(
  animal => new { animal = animal, nameLength = animal.Length })
.Where(x => x.nameLength > 3)
.OrderBy(y => y.nameLength)
.Select(z => z.animal);