Calling a Java class to the main class for execution

A

Andy

Say I have 2 files -

addition.java
negation.java

Now in the main class (say controlpanel.java) I want something like
this -

Print -" You want addition? Press 1"
" You want negation? Press 2"

then it should run addition.java when the user inputs 1 or negation if
the user inputs 2

Basically, the user will enter information (like a=1 and b=2 for a+b)
in addition.java (or negation.java) and not controlpanel.java

controlpanel.java is the main class to forward the user to a
particular class for operation. All these classes are under the same
Netbeans package.

How can this be done? This is basic and I couldn't figure it out :
( Switch statements were clueless about running classes from a main
class.

Thanks a lot!
 
S

Sabine Dinis Blochberger

Andy said:
Say I have 2 files -

addition.java
negation.java

Now in the main class (say controlpanel.java) I want something like
this -
Make all your classes part of a package.
How can this be done? This is basic and I couldn't figure it out :
( Switch statements were clueless about running classes from a main
class.
You don't "run" a class, you most usually instantiate it into an object.
Then you use the methods to do stuff.

You *can* use class methods without instantiating, but it depends on
your design.
Thanks a lot!

Please refer to Suns Java tutorial to learn about classes and objects:
http://java.sun.com/docs/books/tutorial

specifically
http://java.sun.com/docs/books/tutorial/java/javaOO/index.html
 
A

Andrew Thompson

Andy said:
Say I have 2 files -

"You have 2 files" OK.. getting back to being serious.
addition.java
negation.java

Class names in Java should be EachWordUpperCase,
so these class names should be Addition.java and
Subtraction.java rather than addition/subtraction or
addition/negation.
Now in the main class (say controlpanel.java) I want something like
this -

Print -" You want addition? Press 1"
" You want negation? Press 2"

then it should run addition.java when the user inputs 1 or negation if
the user inputs 2

if (result==1) {
// call main constructor
Addition addition = new Addition();
} else {
Subtraction subtraction = new Subtraction();
}
Basically, the user will enter information (like a=1 and b=2 for a+b)
in addition.java (or negation.java) and not controlpanel.java

In that case, there is little reason to call the main methods
of the other classes, just construct and use the methods
they have from the (single) 'main' class.
controlpanel.java is the main class to forward the user to a
particular class for operation. All these classes are under the same
Netbeans package.

So that means they are in the same Java package?
In that case, there will be no 'import's needed.
How can this be done? This is basic and I couldn't figure it out :
( Switch statements were clueless about running classes from a main
class.

Huhh? What does that mean?
Are you referring to using a switch to select the
class to run? It could be done that way.
 
A

Are Nybakk

Andy said:
Say I have 2 files -

addition.java
negation.java

Now in the main class (say controlpanel.java) I want something like
this -

Print -" You want addition? Press 1"
" You want negation? Press 2"

then it should run addition.java when the user inputs 1 or negation if
the user inputs 2

Basically, the user will enter information (like a=1 and b=2 for a+b)
in addition.java (or negation.java) and not controlpanel.java

controlpanel.java is the main class to forward the user to a
particular class for operation. All these classes are under the same
Netbeans package.

How can this be done? This is basic and I couldn't figure it out :
( Switch statements were clueless about running classes from a main
class.

Thanks a lot!

By creating objects?

Or did you mean loading compiled code (.class)? If so, look up
Class.forName(String)
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Members online

Forum statistics

Threads
473,744
Messages
2,569,479
Members
44,899
Latest member
RodneyMcAu

Latest Threads

Top