Hi all,
I am a little bit confused about how to import package correctly. Typically, ".*" means all ,right ? However, some of the cases I read in java books actually import detail class(es) ot the same package when this package is imported at the same time. For example,
import java.awt.*
import java.awt.event.*
Please help me out. Thanks.
AFAIK, importing is not recursive. If a package has subpackages and you need them, you have to import them separately.
importing java.awt.* does NOT import anything in java.awt.event. It only imports classes at the java.awt level. Packages are NOT hierarchical.
In addition, if you do, say, this:
import java.util.*;
import java.sql.*;
then you'll have to explicitly import java.util.Date or java.sql.Date if you want to use one of them without specifying the full package name.
and always be sure that importing all classes doesn't slow down the progress of your program, because importing full packages is just getting a reference to those classes, not loading the classes to your program..(^_^);
> and always be sure that importing all classes doesn't
> slow down the progress of your program, because
> importing full packages is just getting a reference
> to those classes, not loading the classes to your
> program..(^_^);
Importing has absolutely no effect whatsoever at runtime. It's just a way for you to avoid typing out fully.qualified.Names of classes in your source code
> and always be sure that importing all classes doesn't
> slow down the progress of your program,
It never will. Importing has ZERO runtime effect. All it does is tell the compiler that, for examle, "List" means "java.util.List."
> because
> importing full packages is just getting a reference
> to those classes, not loading the classes to your
> program..(^_^);
Importing has nothing to do with loading classes. It has no efect at runtime.
