Default value for a variable in a user defined function

Is it possible to set a default value to a variable in a user defined function?

For example, a simple function like this

function Multiply(array, k = 2)
{
	return k*array;
}

When compiling, the error is "Error 31. Syntax error, unexpected '=', expecting ')' or ','

Thank you for your help!

I found one way to resolve this, using global variable.

But if you have any other solutions, I would love to know!

Default values are only supported by internal functions and functions exported by plugins.