Java things about Def __java

1. Parameter list

Java is actually only two kinds of positional and variable parameters

Neither the keyword parameter nor the default parameter, where the default parameter can also be implemented by overloading the clumsy implementation,
And the keyword parameter seems to have no ...
Just say the variable parameters of the only bright spot:
For example:

void Var_var (Integer ... numbers) {for
    (int i=0;i<numbers.length,++i) {
        System.out.println (numbers[i]);
}

Var_var (1,2,3,4);

The variable parameter uses exactly the same array in the function 2. return value

If only one return value is allowed, there is no reference to C C + + what is it, but you can not even a tuple (tuple) will not
The definition in the API is a few meanings.

Anyway, either define a class, return the class, or hang directly on the class's properties
Or, in addition to immutable objects (string, etc) like (linkedlist,arraylist), variable objects can modify internal values within a function