Explanation of Select() and SelectMany() in LINQ

One common interview question in LINQ is about the difference between Select() and SelectMany() methods. Let's break it down:

Select() Method:

The Select() method is used to transform each element of a collection into a new form. It applies a transformation function to each element and returns a new collection with the transformed elements.

SelectMany() Method:

The SelectMany() method is used to flatten a collection of collections. It is often used when dealing with nested collections or when you want to combine multiple collections into a single collection.

In summary, Select() is for transforming elements in a single collection, while SelectMany() is for flattening nested collections.

Understanding the difference between Select() and SelectMany() in LINQ is essential for writing efficient and effective LINQ queries.