Is ToList slow?

Is ToList slow?

ToList() , that is when the query is executed. And that is the reason why it is slow, because only when you call . ToList() is the query executed by your database. It is called Deferred execution.

Should I use ToList ()?

ToList() is usually preferred if you use it on IEnumerable (from ORM, for instance). If the length of sequence is not known at the beginning, ToArray() creates dynamic-length collection like List and then converts it to array, which takes extra time.

When should I call ToList?

Call ToList if: you create new objects (eg. in a select) you have side effects in your query.

What does ToList () do in C#?

This extension method converts collections (IEnumerables) to List instances. It is fast and easy-to-remember. It returns a List instance with the appropriate elements.

Is IQueryable faster than list?

GetList(context) might return an object backed by a custom LINQ provider (like an Entity Framework collection), then you probably want to leave the data cast as an IQueryable: even though your benchmark shows it being 20 times faster to use a list, that difference is so small that no user is ever going to be able to …

What is ToListAsync?

ToListAsync(IQueryable) Creates a List from an IQueryable by enumerating it asynchronously.

Should I use list or IEnumerable?

In terms of performance, the answer is it depends. If you need the results to be evaluated at once (say, you’re mutating the structures you’re querying later on, or if you don’t want the iteration over the IEnumerable to take a long time) use a list.

How do you use Tolist in Python?

tolist() function return a list of the values. These are each a scalar type, which is a Python scalar (for str, int, float) or a pandas scalar (for Timestamp/Timedelta/Interval/Period). Example #1: Use Index. tolist() function to convert the index into a list.

What is ToList in Linq?

LINQ ToList() Method In LINQ, the ToList operator takes the element from the given source, and it returns a new List. So, in this case, input would be converted to type List.

Does ToList create a deep copy?

title)); Create a generic ICloneable interface which you implement in your Book class so that the class knows how to create a copy of itself. Except that does not create a deep copy, it creates a shallow copy.

Does ToList make a copy?

As ToList has no way to clone MyObject, it must do a shallow copy, so the created list contains the same references as the original one, so the code returns 5. ToList will create a brand new list.

Which is better IEnumerable or list?