How do I find the IGrouping value?

First you need to select the desired group. Then you can use the ToList method of on the group. The IGrouping is a IEnumerable of the values.

What is IGrouping?

An IGrouping is an IEnumerable that additionally has a key. The key represents the attribute that is common to each value in the IGrouping. The values of an IGrouping are accessed much as the elements of an IEnumerable are accessed.

How GroupBy works c#?

The GroupBy operator returns a group of elements from the given collection based on some key value. Each group is represented by IGrouping object. Also, the GroupBy method has eight overload methods, so you can use appropriate extension method based on your requirement in method syntax.

What is ILookup C#?

ILookup entries can contain multiple items per key – each key is mapped to an IEnumerable . Also as hinted to in the comments an ILookup is immutable, while you can update values in an IDictionary (it exposes an Add() method and an indexer that allows getting and setting values).

What is LINQ key?

The key is the object that is used in the ‘group’ method. It can be used to produce a dictionary object Dictionary where the key is the first string.

What is meant by LINQ in C#?

Language-Integrated Query (LINQ) is the name for a set of technologies based on the integration of query capabilities directly into the C# language. Traditionally, queries against data are expressed as simple strings without type checking at compile time or IntelliSense support.

What is Linq lookup?

LINQ ToLookup() Method ToLookup operator in LINQ is an extension method, and it is used to extract a set of key/value pairs from the source. Here, each element in the resultant collection is a generic Lookup object. Lookup object holds the Key and subsequence items that matched with the Key.

What can I use instead of dictionary in C#?

A HashSet, similar to a Dictionary, is a hash-based collection, so look ups are very fast with O(1). But unlike a dictionary, it doesn’t store key/value pairs; it only stores values. So, every objects should be unique and this is determined by the value returned from the GetHashCode method.

What is GroupBy in LINQ?

Grouping is a very powerful feature provided by LINQ that transforms a collection in groups where each group has a key associated with it. Note: GroupBy performs a deferred execution which means the query is only executed when the records are processed using a foreach loop.


LINQ to SQL is an object-relational mapping (ORM) implementation that allows the direct 1-1 mapping of a Microsoft SQL Server database to . NET classes, and query of the resulting objects using LINQ.

Why LINQ is used?

Readable code: LINQ makes the code more readable so other developers can easily understand and maintain it. Standardized way of querying multiple data sources: The same LINQ syntax can be used to query multiple data sources. Compile time safety of queries: It provides type checking of objects at compile time.

What is meant by lookup table?

A lookup table is an array of data that maps input values to output values, thereby approximating a mathematical function. Given a set of input values, a lookup operation retrieves the corresponding output values from the table.