C#: params keyword vs. list

Question

What are the pro/cons of using the params keyword vs. a List as input to some c# function? Mainly what are the performance considerations and other trade offs.

Accepted Answer

The params keyword is syntactic sugar handled by the C# compiler. underneath the hood, it's actually turning

```
void Foo(params object[] a) { ... }
Foo(1,2,"THREE");
```

into

```
void Foo(object[] a) { ... }
Foo(new object[] { 1, 2, "THREE" })
```

From a performance perspective like you're asking about, the params call is simply faster because it is a bit faster to create an array than it is to create a List<>. There is no performance difference between the two snippets above.

C#: params keyword vs. list

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