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Five example Java programs

Once you login, and have run the sample
program, you are ready to write you
own Java programs.  Below are five
simple programs designed to
demonstrate different aspects of
the JJ system such as

- Input/Output,

- running programs without any methods,

- running programs with methods but no class,

- running programs using classes

JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ
JJ                                       JJ
JJ  Five Java examples to run using JJ   JJ
JJ                                       JJ
JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ

------------------------------------
1. Modify the one line Hello program
------------------------------------

System.out.println("Hello <your name here>");

---------------------------------
2. Using the JJS input and output
---------------------------------

int num;
JJS.outputlnString("Please enter a number.");
num = JJS.inputInt();
System.out.println(num);
JJS.outputString("Your number times 11 is ");
JJS.outputlnInt(num * 10);

---------------------------------------------
2.5 Test thoroughly and SUBMIT your solution.
---------------------------------------------

After running the above program, and making sure
it runs the way you want it to (test a positive
value, a negative value, and zero) press Submit
on the RunIt page to submit the program to your
instructor (in this case, that's me :)

Notice that students will learn from the beginning
that submitting "code only" is not enough, and
that the teacher is going to see all the testing,
all the input and all the output.

-----------------------------------
3. The Hello program using a method
-----------------------------------

void myMain() {
JJS.start();
System.out.println("Hello JJ again");
}

--------------------------------------------
3.5 From commands only to commands inside of
methods.
--------------------------------------------

This style of running JJ using JJS.start()
in a method (afterall, there will be more
than one method so you need to tell JJ which
method is the "starting" method) is handy
for those that want to step into classes
as follows:
 1. show commands only
 2. introduce methods (put all commands into
    a single method)
 3. many methods, but still no class
 4. introduce putting methods inside a "class"
 5. finally, classes that use other classes

----------------------------------
4. The Hello program using a class
----------------------------------

class MyFirstClass {

public void myMain() {
  JJS.start();
  System.out.println("Hello JJ once again");
 }//end myMain

}//end class

-----------------------------
5. Shows 2 methods in a class
-----------------------------

class MySecondClass {

public void anotherMain() {
  int num;
   JJS.start();
   JJS.outputlnString("Please enter a number.");
   num = JJS.inputInt();
   System.out.println(num);
   JJS.outputString("Your number squared is ");
   JJS.outputlnInt(squareIt(num));
 }//end anotherMain

private int squareIt(int n) {
  int result;
   result = n * n;
   return result;
 }//end squareIt

}//end class

---------------------------------------------
5.5 Test thoroughly and SUBMIT your solution.
---------------------------------------------

After running the above program, and making sure
it runs the way you want it to (test a positive
value, a negative value, and zero) change the
word "squared" in the JJS.outputString command
to "cubed" and make the appropriate changes
so that the input number is cubed instead
of squared ... if input is 3, output is
Your number cubed is 27
After thoroughly testing, press Submit on the
RunIt page to submit the program.

After exploring
the various features
built into JJ
you are ready
to run some more
interesting
programs

SCROLL through
the text on the
left and you will
find 5 example
program that you
can copy and paste
into the JJ CodeIt
page

Sadly, this is
the end of this
introduction to
JJ

More walkthroughs
will be available
soon