How to skip optional parameters in C#?

Example:

public int foo(int x, int optionalY = 1, int optionalZ = 2) { ... }

I'd like to call it like this:

int returnVal = foo(5,,8); 

In other words, I want to provide x and z, but I want to use the default for Y, optionalY = 1.

Visual Studio does not like the ,,

Please help.

If this is C# 4.0, you can use named arguments feature:

foo(x: 5, optionalZ: 8); 

See this blog for more information.

In C# 4.0 you can name the arguments occurring after skipped defaults like this:

int returnVal = foo(5, optionalZ: 8);

This is called as named arguments. Several others languages provide this feature, and it's common form them to use the syntax foo(5, optionalZ=8) instead, which is useful to know when reading code in other languages.