How is duck typing different from the old 'variant' type and/or interfaces?

Question

I keep seeing the phrase \"duck typing\" bandied about, and even ran across a code example or two. I am way too lazy busy to do my own research, can someone tel

Answer 1

Try reading the very first paragraph of the Wikipedia article on duck typing.
Duck typing on Wikipedia

I can have an interface (IRunnable) that defines the method Run().
If I have another class with a method like this:
public void RunSomeRunnable(IRunnable rn) { ... }

In a duck type friendly language I could pass in any class that had a Run() method into the RunSomeRunnable() method.
In a statically typed language the class being passed into RunSomeRunnable needs to explicitly implement the IRunnable interface.

"If it Run() like a duck"

variant is more like object in .NET at least.