How to get value from IGrouping c#?

How to get value from IGrouping c#?

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 an 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.

What is Linq key?

The key is the thing that is common in your group. For example if you have a sequence of words and want to group all words on their first letter, then you have a group with words that start with the letter ‘a’, and a group with words that start with the letter ‘b’ etc.

How do you use select many?

SelectMany() method For example, SelectMany() can turn a two-dimensional array into a single sequence of values, as shown in this example: int[][] arrays = { new[] {1, 2, 3}, new[] {4}, new[] {5, 6, 7, 8}, new[] {12, 14} }; // Will return { 1, 2, 3, 4, 5, 6, 7, 8, 12, 14 } IEnumerable result = arrays.

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).

How does GroupBy work C#?

Group by works by taking whatever you are grouping and putting it into a collection of items that match the key you specify in your group by clause. You wouldn’t typically want to just select the grouping directly.

What does LINQ GroupBy return?

The GroupBy operator returns a group of elements from the given collection based on some key value. Each group is represented by IGrouping object. A LINQ query can end with a GroupBy or Select clause. …

What is the difference between select and SelectMany C#?

Select is used to select value from a collection whereas SelectMany is used to select values from a collection of collection i.e. nested collection.

How do you flatten a list in C#?

We can use LINQ’s SelectMany() method to map each element of a list to an IEnumerable and flattens the resulting sequences into a single list.

How do you use ToDictionary?

The ToDictionary() method has an overload that takes two lambda expressions (nitpick: delegates); one for the key and one for the value. For example: var myDic = GetSomeStrings(). ToDictionary(x => x, x => x.