- · First-returns one element in the collection;
- · FirstOrDefault-Returns the first element in the collection (returns the default value if none);
- · Last-Returns the final element in the collection;
- · LastOrDefault-Returns the last element in the collection (default value if not)
- · ElementAt-Returns the element of the specified index in the collection;
- · Elementatordefault-Returns the element of the specified index in the collection (if not, returns the default value);
- · Contains-Determines whether a set contains an element;
- · Any-determines whether an element in the set satisfies a condition;
- · All-Determines whether all elements in the collection meet a certain condition;
- · Count-Returns the number of elements in the collection, returns an int;
- · LongCount-Returns the number of elements in the collection, returns a long;
- · Sum-The collection should be a collection of numeric types, and no delay
- · Min-Returns the minimum value of the collection;
- · Max-Returns the maximum value of the collection;
- · Average-The collection should be a collection of numeric types, averaging; no delay
- · Aggregate-Gets an aggregate value based on the input expression, without delay
- · Cast-Converts the collection to a strongly typed collection;
- · DefaultIfEmpty-The default value is returned when the query result is empty;
- · SequenceEqual-Determines whether two sets are the same;
- · OfType-Filters The specified type in the collection;
- · ToArray-Converts the collection to an array;
- · ToList-Converts the collection to a List<t> collection;
- · ToDictionary-Converts the collection to <k, v> collection;
LINQ Query Operations appended first, FirstOrDefault, last, LastOrDefault, ElementAt, Elementatordefault, Contains, any, all, Coun