Java Reference
In-Depth Information
Files are stored in folders or directories. These file containers can be nested. That is,
a folder can contain not only files but also other folders, which themselves can
contain more files and folders (see
Figure 9
). This hierarchy can be quite large,
especially on networked computers, where some of the files may be on your lo
cal
disk, others elsewhere on the network. While you need not be concerned with
every
branch of the hierarchy, you should familiarize yourself with your local
environment. Different systems have different ways of showing files and directories.
Some use a graphical display and let you move around by clicking the mouse on
folder icons. In other systems, you must enter commands to visit or inspect different
locations.
14
15
Step 4. Write a Simple Program
In the next section, we will introduce a very simple program. You will need to learn
how to type it in, how to run it, and how to fix mistakes.
Step 5. Save Your Work
You will spend many hours typing Java program code and improving it. The
resulting program files have some value, and you should treat them as you would
other important property. A conscientious safety strategy is particularly important
for computer files. They are more fragile than paper documents or other more
tangible objects. It is easy to delete a file accidentally, and occasionally files are lost
because of a computer malfunction. Unless you keep a copy, you must then retype
the contents. Because you probably won't remember the entire file, you will likely
find yourself spending almost as much time as you did to enter and improve it in the
first place. This costs time, and it may cause you to miss deadlines. It is therefore
crucial that you learn how to safeguard files and that you get in the habit of doing so
before disaster strikes. You can make safety or backup copies of files by saving
copies on a floppy or CD, into another folder, to your local area network, or on the
Internet.
Develop a strategy for keeping backup copies of your work before disaster strikes.
