I pass the Simple Test. But I am stack on other tessts. And test error also describe something like the following.

  Failed! - Expected: { c: 1, d: 1 }, instead got: { d: 1 }

So, I try random like the following

var a =  { c: 1, d: 1 }
var b = a.assign(a);
Object {c: 1, d: 1}

I got what I expected? Can you describe a little more on description?

I am not familar with random tests. Can you explain me a little bit with example? It will be very helpful to me. Thanks

There is no other way to improve?

Doing pretty well with One line is super! :)

You got Clever :)

I got it now. Thanks

I don't understand. Sum is 24 and difference is 4. So, age difference can be [20,4] as well?

"2" is not a number. It's a string?