CODEWITHSUNDEEP
c#
Elad Benda
Elad Benda

Reputation: 36664

sending a collection's items to some method as params[] vars

I have a method foo(params[] items)

I have a collection (List, Set, ...) I want to send its items to foo as items

what syntax can I use?

Upvotes: 4

Views: 70

Answers (2)

Piotr Auguscik
Piotr Auguscik

Reputation: 3681

If you pass array as only param it will be passed as items. So just use Collection.ToArray. Actually there is something good to know about when you're using params. If you pass null with intention to pass it as first and only param it will be used as null array. So with code like this:

SomeMethod(null);

public void SomeMethod(params object[] items)
{
...
}

Items will be null, not array with length of 1 and null as first elem.

Upvotes: 4

Grant Thomas
Grant Thomas

Reputation: 45058

That method signature is invalid, so it won't compile. You still need to specify the type of the items, for instance:

foo(params string[] items) { }

then you can call it simply enough:

foo("one", "two", "three");
foo(new string { "one", "two", "three"});
foo(myCollection.ToArray());

Or,

foo(myArrayOfStrings);

Where myArrayOfStrings is an array of strings.

You should also be sure to check for a null argument prior to iterating the items, since,

foo(null);

is valid.

Upvotes: 1

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