File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
http://aspose.com/file-tools
The moose likes Beginning Java and the fly likes Variable name generation Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


Win a copy of Spring in Action this week in the Spring forum!
JavaRanch » Java Forums » Java » Beginning Java
Bookmark "Variable name generation" Watch "Variable name generation" New topic
Author

Variable name generation

Mikael Saltzman
Greenhorn

Joined: Dec 07, 2012
Posts: 9
Hi!

Suppose I have a variable: .

Is there a way to change the name of this variable (the identifier, not the type)?

Guess that would be great for loops. For example, when I need to add multiple swing component to a container programmatically: e.g. JMenuItems to a JMenu.

I know it's possible to create a loop and add menu items from one variable being created anew for each iteration, but then these menu items will be anonymous, right?

So I guess there are two questions here: 1. Can I change variable name through automated name generation? 2. Can I assign events and such to an anonymously added menuItem after it has been added to a menu?

Thanks for reading!
fred rosenberger
lowercase baba
Bartender

Joined: Oct 02, 2003
Posts: 11402
    
  16

variable names are used by the developer, not the JVM.

tell me...what good would it do to dynamically come up with a name like 'component2' in a loop. You don't have any way to reference that variable later, unless you (again) dynamically regenerate the names, which just seems like a bad idea on so many levels.

If you want a bunch of objects, that is what a collection is for. An ArrayList will hold all of them, and let you reference them later. Or you could use a Map. or a linked list...or any of the other dozen (or so) collection types, which makes much more sense than programatically coming up with a variable name on the fly.


There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors
Paul Clapham
Bartender

Joined: Oct 14, 2005
Posts: 18651
    
    8

Mikael Saltzman wrote:2. Can I assign events and such to an anonymously added menuItem after it has been added to a menu?


Sure you can. Remember that you're adding a reference to the JMenuItem object to the menu, not a reference to a variable. So if there's a JMenu method which returns that reference, then simply assign the reference to a local variable and do whatever you like with it. The fact that elsewhere in the program you assigned that reference to some other variable means nothing.
Mikael Saltzman
Greenhorn

Joined: Dec 07, 2012
Posts: 9
Thanks both of you! Crystal clear! Classic mistake to start to think of variables (pointing at objects) as containers rather than object references. JMenu's getItem() method saved me a lot of code here, which is in line with the suggestion to look into the container class' ability to access contained objects through get methods.
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: Variable name generation