Javascript function return logic

Question

I came across this function code in a javascript library and not really sure how the return works.

    function(t, e, r) {
     return 2 === arguments.length && "function" == typeof e &&   (r = e,e =null)  ,   Cn(t, e, n, r)
    }

Is it equivalent to the following if statement?

    
     if(2 === arguments.length && "function" == typeof e) 
          (r = e,e = null)  ,  return  Cn(t, e, n, r)