Aggregation Operators

Aggregation operators reduce a whole sequence down to a single value: a count, a sum, the largest item, the first match. They sit at the end of a LINQ pipeline and force the query to run, which makes them the punctuation marks of LINQ. This lesson walks through every aggregation operator in the standard library: counting, summing, min/max, averaging, folding with Aggregate, the quantifier operators (Any, All, Contains), and the element operators (First, Single, Last, ElementAt).