Chat Transcript, May 30, 1997

[Rob] joins at Thu May 29 21:41:57 1997 from

Rob=> Hello

[wachsmut] joins at Thu May 29 21:44:54 1997 from

wachsmut=> Hi Rob ...
Rob=> hi bert
wachsmut=> looks like we are still short ...
Rob=> I've had a good time playing today with Java
wachsmut=> Great ... you'll probably be bored out of your mind for the first week...
Rob=> It gives me a chance to explore a bit. No problem.

[Yan Yu Zeng] joins at Thu May 29 21:46:30 1997 from
[Jenn] joins at Thu May 29 21:46:40 1997 from

wachsmut=> Hi Yan Yu, what are you doing here - welcome !

[Don] joins at Thu May 29 21:46:49 1997 from

Rob=> here they come
wachsmut=> Looks like we're filling up ... great !
Yan Yu Zeng=> I just watch what happened in your chat room.
wachsmut=> Alright, sounds good - you're more than welcome !
wachsmut=> Hi Jenn and Don, are you there ?

[David] joins at Thu May 29 21:47:59 1997 from

Don=> yes
wachsmut=> David, good to 'see' you too
David=> hello
Jenn=> Hi
wachsmut=> Alright, we've established contact....
wachsmut=> let's wait for a few more minutes ...
Don=> I have a question. If I telnet to scirur from work, should I be able to run netscape mono?
wachsmut=> maybe somebody else will join ....
wachsmut=> Actually, with Telnet you can't run Graphics programs
wachsmut=> on sciris, remember ?
wachsmut=> Netscape won't work, neither will the applet viewer ....
wachsmut=> only 'text based' program will work with Telnet ...
wachsmut=> 3 more minutes, then we start for real, alright ?
David=> sounds good
Don=> yeah, but I was just testing those example from the lecture, but netscape wouldn't come up
wachsmut=> Right ... using Telnet, you can't start Netscape ....
wachsmut=> but we don't need to, at least not in the first week ....
Rob=> You can use telnet in to run pico and create and run Java applications
wachsmut=> Excatly ! That's in fact what we'll do today .....
Rob=> sorry, I mean you can telnet in to .....
wachsmut=> So ... might as well start with the 'Lecture' ....
wachsmut=> Everybody there - please say 'hi', or 'yes', or 'whatever' ...
Rob=> hi
Jenn=> hi
David=> Hi
wachsmut=> hmmmm .... Don ?
wachsmut=> Well ...
wachsmut=> Alright ...
Yan Yu Zeng=> Hi, You have already in old portfolios.
Don=> yes
Don=> I sent it once?
wachsmut=> attendence is somewhat disappointing, but here's what I want
wachsmut=> to do today....
wachsmut=> I want to run through a couple of question
wachsmut=> about the first lecture ....
wachsmut=> please answer any time !!!
wachsmut=> What does every Java program start out with ?
David=> class name
Yan Yu Zeng=> Hi, world!
wachsmut=> and then ....
wachsmut=> every program start with:
wachsmut=> class ClassName
wachsmut=> {
wachsmut=> public static void main(String args[])
wachsmut=> { ... blah blah }
wachsmut=> }
wachsmut=> }
David=> then, public statement
wachsmut=> That's *every* program !
Rob=> then {
wachsmut=> Yes, there can be more,
wachsmut=> but that's the least every program *must* have ....
wachsmut=> Next: what are the basic data types in Java ?
Yan Yu Zeng=> Every application must have main(), like c and C++
Rob=> The usual: int float double ....
David=> double
wachsmut=> boolean (which is not available in C++)
wachsmut=> Great.... here's another one ....
David=> char
wachsmut=> where do you declare a variable ?
David=> anywhere you want
wachsmut=> Great ... David's done the reading, clearly ....
Rob=> First real line of the program? (For good style?)
Don=> my send button is clogged
Yan Yu Zeng=> before you use var
wachsmut=> Type 'RETURN' instead of clickin on Send !
Don=> now it seems ok
wachsmut=> Actually, variable can, and should, go right where you need them.
Rob=> ok
wachsmut=> Not at the beginning, not anywhere else.
wachsmut=> When you need a variable, declare it. There's something else
wachsmut=> called 'Fields', which we get to later, that is usually declared
Yan Yu Zeng=> class
wachsmut=> at the beginning of the class ... but that's for next time -:)
wachsmut=> Alright: What does 'x++' or 'x--' stand for ?
Don=> doesn't that it make it hard to see where they are defined though
wachsmut=> Yes, kind of true. But, if you need a varialbe somewhere in
Don=> subtracting or adding one to the variablex, like a counter
Jenn=> it adds or subtracts one from the variable
wachsmut=> the program, chances are that it's not important anyway ...
wachsmut=> and therefore, no need to really bother anyone with it
wachsmut=> at the beginning. Counting variables in a loop are a
wachsmut=> good example .... it's pompous to declare them at
wachsmut=> the beginning ... big deal for nothign, don't you think ?
wachsmut=> And yes, Jenn, that's right, thanks !
wachsmut=> Two more:
wachsmut=> Give me an example of how a 'for' loop starts out ....
wachsmut=> anything will do, as long as the syntax is right ....
Don=> for x = 1 to 10
wachsmut=> Nope
Yan Yu Zeng=> for (i=0;i<=3;++i){ do sth here}
wachsmut=> better
Jenn=> for(i=1; i<=3; i++)
Rob=> What about declaring that i?
Yan Yu Zeng=> same
wachsmut=> Right ... thanks Jenn and Yan Yu ... let's look at that closely:
Don=> for (int i=0;i<10;i++)
wachsmut=> so you say: for (int i = 0; ....
wachsmut=> that means you are declaring a variable i as integer right
Yan Yu Zeng=> yes
wachsmut=> when you need it,
wachsmut=> and you are also initializing it to, say, 0, at that time.
Rob=> I don't mean to carry on this declaring business too much, but
wachsmut=> That's good, because chances are that the 'i' variable
Yan Yu Zeng=> I may declare it at begin or int i
Rob=> what about the next time you use a for in the same program?
wachsmut=> Ah, rob, good question:
Rob=> And want to use the same counter variable?
wachsmut=> every variable declared is only valid in the 'group'
wachsmut=> that it has been declared in.
wachsmut=> After that, it becomes undefined and can be reused.
Rob=> What's a group?
wachsmut=> For example:
Don=> as long as it's not in the same loop, he's ok right?
wachsmut=> Right
David=> different names?
wachsmut=> Here's an example:
wachsmut=> for (int i=0; i<10; i++)
wachsmut=> {
wachsmut=> System.out.println(i);
wachsmut=> }
wachsmut=> for (int i = 10; i > 0; i--)
wachsmut=> {
wachsmut=> System.out.println(i);
wachsmut=> }
wachsmut=> can all be in one class (or program) just fine.
wachsmut=> The first i is valid only in the first loop, the second one
wachsmut=> only in the second loop.
David=> ok
Rob=> Hmmm. Different than C.
wachsmut=> First loop counts up, second one counts down....
wachsmut=> Alright, I have one more quick question:
wachsmut=> give me a basic 'while' loop, anything, as long as
wachsmut=> the syntax is right.
Don=> int i = 0;
Don=> while (i <10)
Don=> {
Yan Yu Zeng=> int i=0; while(i<=10){do sth here;i++}
Don=> some processing...
Don=> i++;
Don=> }
wachsmut=> Good.... the basic point here is that a while loop needs three
wachsmut=> things:

[James McGirr] joins at Thu May 29 22:08:20 1997 from

wachsmut=> - an initialization part outside the loop
wachsmut=> - a test condition
wachsmut=> - a modification inside the loop
wachsmut=> Just like Don said.
wachsmut=> Hi James - I'll post a transcript of the
wachsmut=> session when we're done, don't worry ....
wachsmut=> Alright, now .... I have three 'jobs' lined up,
wachsmut=> but first: any questions ?
wachsmut=> you can ask questions as well, after all -:)
James McGirr=> I was a little unsure of the structure of an array
Don=> is there a way to see the typing line and also the bottom of this screen?
wachsmut=> Alright, arrays are for the next lecture, to be posted tonight !
wachsmut=> Maximize your screen ?
Yan Yu Zeng=> keep use clear
Don=> it is

[David] leaves at Thu May 29 22:10:17 1997

wachsmut=> Sorry, maximize the Netscape Window ?
wachsmut=> Oh well .... I'll 'shrink' the applet, next time it will be fine.

[David] joins at Thu May 29 22:10:44 1997 from

wachsmut=> It's right now sized for an 800 x 600 screen. ....
Don=> no big deal, the clear works, thanks
Rob=> Don, try to better position the rightmost scroll bar.
wachsmut=> Also, on Netscape, go to options, and 'uncheck' the buttons, location
wachsmut=> and directory stuff to have more room to see.

[Rob] leaves at Thu May 29 22:11:17 1997

wachsmut=> That's the only question ? Doing fine, then ?

[Jenn] leaves at Thu May 29 22:11:35 1997
[Rob] joins at Thu May 29 22:11:36 1997 from

wachsmut=> Alright ... here's your first job:
wachsmut=> Please wait until I say 'GO' ...
wachsmut=> You need to create a homepage on Sciris
wachsmut=> Here are the instructions:

[Jenn] joins at Thu May 29 22:12:26 1997 from

wachsmut=> Keep Netscape active, but minimize it (not now !)
wachsmut=> start Telnet, connect to Sciris, login
wachsmut=> create a directory called 'public_html' in your account
wachsmut=> switch into that directory
Jenn=> i don't have a sciris account yet..
Yan Yu Zeng=> How to set right path for run java on our own machine?
wachsmut=> start pico and create a file named 'index.html'
wachsmut=> Add some HTML code, save it.
wachsmut=> switch back to Netscape
wachsmut=> Now
wachsmut=> for help on creating HTML code, look to the menu on the left (but don't
wachsmut=> click on anything yet) ...
wachsmut=> See the 'HINT' link ? Don't use it quite yet ....
wachsmut=> It will tell you how to create a homepage.
wachsmut=> So, are you ready to roll ?
wachsmut=> say 'yes', or ask a question, everybody ...
James McGirr=> yep
wachsmut=> Don, that's a 'yes', I assume ?
Don=> yes
Jenn=> i need an account...
wachsmut=> Rob, David ?
Yan Yu Zeng=> Question: how to set right path in order to run java in our own computer?
wachsmut=> Jenn, it's setup I think.
wachsmut=> account name should be agasjenn, password 'seton1' ...
Jenn=> ok
wachsmut=> everybody ready to create their homepage now ?
wachsmut=> I give you 10 minutes. Minimize Netscape, start Telnet,
wachsmut=> do your thing, be back here at exactly 10:28 !
wachsmut=> It's now 10:17 on my watch.
wachsmut=> GO for it !
Rob=> Hi Bert... I'm back. Do you want us to do any chmod?
wachsmut=> If you have questions, come back earlier, of course, and ask.
wachsmut=> no 'chmod' necessary, rights are correct by 'default' (I hope)...

[James] joins at Thu May 29 22:17:59 1997 from
[wachsmut] leaves at Thu May 29 22:18:12 1997
[wachsmut] joins at Thu May 29 22:18:24 1997 from

David=> my HTML needs work
Don=> i can't fdind telnet
wachsmut=> Well, check the HINT on the left side (the menu item)
wachsmut=> you will loggout of CHAT, but can 'Join' any time later....

[Jenn] leaves at Thu May 29 22:19:04 1997

wachsmut=> go to start
wachsmut=> pick 'run'

[Rob] leaves at Thu May 29 22:19:21 1997

wachsmut=> type 'telnet.exe'

[James] leaves at Thu May 29 22:20:06 1997

wachsmut=> Don, are you login into sciris yet ?

[Rob] joins at Thu May 29 22:20:29 1997 from
[Don] leaves at Thu May 29 22:20:52 1997 (UNEXPECTED ERROR: client not found in list.)

wachsmut=> David, how about you ?

[wachsmut] leaves at Thu May 29 22:21:06 1997

David=> someone give some simple html lines, please

[wachsmut] joins at Thu May 29 22:21:14 1997 from

David=> i have created index.html, but html..i will work on later
wachsmut=> No problem ....
wachsmut=> as long as you have that file, and that directory, you're okay ...
David=> done
wachsmut=> and you can add more code later - in fact, you'll have to -:)
wachsmut=> Alright, let's wait until the others are back ....

[Don] leaves at Thu May 29 22:23:05 1997 (UNEXPECTED ERROR: client not found in list.)

wachsmut=> of course, if you want to chat ....

[Don2] joins at Thu May 29 22:23:38 1997 from

wachsmut=> Don2 ?????
Don2=> I got disconnected somehow
Don2=> i clicked on hints and it said disconected from kitten?
wachsmut=> Strange, you're still on the list somehow ...

[Jenn] joins at Thu May 29 22:24:39 1997 from

David=> my two year old is having trouble getting to sleep tonight, its life!
Don2=> yeah, and i still can't find telnet
wachsmut=> yes, kitten is where the actual 'chat server' software runs ...
wachsmut=> try
wachsmut=> 'Start'
wachsmut=> pick 'RUN'
wachsmut=> type 'Telnet.exe'
wachsmut=> that did not work ??????
Don2=> my fault, i'm a fool
wachsmut=> if you insist .... -:)
David=> Don, i will try sending another email to you tomorrow.
wachsmut=> Sure, David, or post a question, if you like....
wachsmut=> Alright, time's about up....
wachsmut=> who's back ?
Yan Yu Zeng=> I am here

[James] joins at Thu May 29 22:26:31 1997 from

David=> Here
Rob=> I'm here.
James=> done
wachsmut=> Jenn ?
Jenn=> i'm here
wachsmut=> Cool ... all successfull ?
James=> i think so
Rob=> I think so. What's the URL, so I can check it.
Jenn=> i think so..
wachsmut=> You're new homepage is now: ...
wachsmut=> where 'username' is your Sciris username.
wachsmut=> Check it now or later, but I'll check it anyway a little
James=> I have a question, is there a way to use netscape on AOL
wachsmut=> later to see if it worked.
Yan Yu Zeng=> yes
wachsmut=> James, I think so, why not ?
James=> I keep getting a winsock error
Yan Yu Zeng=> but ,you aol must latest version

[Don2] leaves at Thu May 29 22:29:18 1997

wachsmut=> If you have a problem with AOL, maybe 'post' it, and I see what I can do...
James=> ok, thanks
Yan Yu Zeng=> 32 bits
James=> yep
James=> aol 3.0
wachsmut=> Right now, there's three more things to do before I'll let you go.
wachsmut=> Again, I'll outline what I have in mind first,
wachsmut=> then let's see if there are any questions,
wachsmut=> and then that's that ....
wachsmut=> Alright, here we go:
wachsmut=> you are to create a directory called 'assign1'
wachsmut=> inside the directory 'public_html'....
wachsmut=> then switch into the assign1 directory via the 'cd'
wachsmut=> command....
wachsmut=> then start pico to create three Java programs,
wachsmut=> one after the other, of course.
wachsmut=> First one: named '' does the following:
wachsmut=> write a program that prints out the first 20 numbers togehter with
wachsmut=> their squares, in reverse order. Save that program as in 'assign1'
wachsmut=> Next Task: save as '' in 'assign1', and create a program that
wachsmut=> computes the sum of the first 500 integers and prints out that
wachsmut=> sum only. Save as '' inside 'assign1'.
wachsmut=> Last: Create a program saved as '' inside assign1 that does
wachsmut=> the following: it starts a while loop, which starts with i = 1.
wachsmut=> Inside the while loop, if i is even, add 3 to i
wachsmut=> if i is odd, add 5 to i.
wachsmut=> Do this until i gets larger than 1000, and tell me what the first number
wachsmut=> is after i gets larger than 1000.
wachsmut=> Alright, you don't have to do this now, of course. It's homework.
wachsmut=> All clear ? (I'll post it again in the discussion area, don't worry).
Rob=> Seems suspiciously similar to the problems in the handout!!!
Rob=> ;)
wachsmut=> Isn't it ?
wachsmut=> Well, we'll start slow, but we'll end strong !
wachsmut=> As for the rest of the homework:

[Don] leaves at Thu May 29 22:35:26 1997 (UNEXPECTED ERROR: client not found in list.)

David=> thank you for not making us do this now!
wachsmut=> I'll put up 'lecture2' tonight .....
wachsmut=> print it, read it, understand it, post questions if any !

[Donny] joins at Thu May 29 22:35:53 1997 from

Donny=> I keep getting disconnect freom kitten
wachsmut=> I'll ask questions on the next chat session, which is ....
wachsmut=> well ...
wachsmut=> my pick is 'Sunday' evening, any objections ?
James=> perfect
wachsmut=> I can be talked into Monday, if necessary ....
wachsmut=> but Sunday's preferred.
wachsmut=> Sunday, say, 8pm ????
Yan Yu Zeng=> yes
Donny=> fine with me
wachsmut=> Any objections ?
Jenn=> sure
Donny=> sounds good
David=> ok
wachsmut=> Alright. Agreed then.
James=> alrighty then
wachsmut=> Again:
wachsmut=> homework is:
wachsmut=> create three slightly different programs
wachsmut=> print and read the lecture
wachsmut=> the lecture - hi, hi, hi - contains 3 or 4 other programs, of course
wachsmut=> do those, if you can, or post questions if you can't
wachsmut=> link all programs into your homepage
Donny=> did you say this chat will be posted?
wachsmut=> and I'll see you back on Sunday, 8pm (hopefully everybody in time -:)
Rob=> Quick question... what's the convention about upper and lower case... for example, what about variables?
wachsmut=> Now, time for 'general questions, griping, and more '''
James=> It took me 30 min to log into AOL
David=> links to these programs in homepage?
wachsmut=> Java's case sensitive !
Rob=> But is there a convention regarding, for example variables?
wachsmut=> For help on HTML, check the 'HINT' on the left side of your screen ....
wachsmut=> Oh, I see ... sorry...
Jenn=> how do you link the programs to your homepage again?
wachsmut=> well, my preference is
wachsmut=> variables start out with small letters, but for a combined word
wachsmut=> I capitalize the next work, as in 'int myScore = 10'. That seems to
wachsmut=> be what most people do.
wachsmut=> Classes are usually capitalized,
wachsmut=> method names (whatever that is) start small, and
wachsmut=> if a combined word, second part is capitalized, as in 'main' (all small),
wachsmut=> or in 'toString' (later)
Rob=> ok... thanks.
wachsmut=> and often, input parameters start with an underscore, as in:
wachsmut=> convertToInteger(_x)
David=> whado you mean by linking programs in homepage
wachsmut=> alright, as to the links:
wachsmut=> you have now (hopefully) a homepage on Sciris
wachsmut=> at the URL '
wachsmut=> You have created a file called 'index.html' in the 'public_html' directory
wachsmut=> on sciris.
wachsmut=> Then, in that file 'index.html', you should add links such that
wachsmut=> when someone click on the link for 'program 1', your source code for
wachsmut=> program 1 (which works correctly) will appear.
wachsmut=> Such a sample 'index.html' file you can find when you
wachsmut=> click on the left side of your screen (the menu for this class),
wachsmut=> and pick the link titled 'HINT' .... it has a brief explainaintion for what
wachsmut=> to do ....
wachsmut=> Well, good thing I can type fast -:)
wachsmut=> Alright, all set to go - or rather, to leave ?
David=> good night all
wachsmut=> Any more questions ? I'll be sticking around for anouther 5 or 10
Yan Yu Zeng=> bye!
Donny=> will the entire chat be posted?
Jenn=> good nite!
wachsmut=> minutes, but feel free to leave any time.

[James] leaves at Thu May 29 22:45:21 1997

wachsmut=> Yes, I'll post the entire 'transcript' (If all the technology worked out ....)
wachsmut=> Night everybody ... thanks for coming !
Donny=> thanks
Rob=> thanks...

[James] joins at Thu May 29 22:46:02 1997 from

James=> where is the transcript for this chat going to be located?

[Donny] leaves at Thu May 29 22:46:32 1997

wachsmut=> good questions ... I'll post in on the bulletin
wachsmut=> board, so people can 'reply' to it, if they want
wachsmut=> I mean the 'discussion' area, sorry ...
David=> understood

[Yan Yu Zeng] leaves at Thu May 29 22:47:11 1997
[Jenn] leaves at Thu May 29 22:47:32 1997

wachsmut=> Alright, anything else I can help you out with, before you'll start
wachsmut=> reading the next lecture, do the assignment, get - hopefully not -
wachsmut=> frustrated .... ?
Rob=> challenged.
wachsmut=> Well, so far I hope not really ... neither frustrated nor challanged !
James=> good night

[James] leaves at Thu May 29 22:49:53 1997

Rob=> I've got my page up, the assign directory created, and some test progs in place
wachsmut=> Well, that's why they call you 'Professor' !!!!!!
Rob=> but the links aren't happening.... I did this fast, so it's likely that I've made a
Rob=> stupid error
wachsmut=> Also, make sure the programs exist first of all ....
Rob=> So much for PROFESSOR!!
Rob=> The exist in assign in public_html
wachsmut=> Is it 'assign' or 'assign1' ?
Rob=> hmmmmm
Rob=> I'll be right back.
wachsmut=> Aha !!!!
wachsmut=> Yep, that's it.
wachsmut=> Your directory is 'assign', but your links refer to 'assign1' ...
wachsmut=> See ... that's the good thing having all your stuff on 'sciris' ... I can check
Rob=> ARGH. Well that saved me some time.... thanks..
wachsmut=> up on everything !
wachsmut=> Alright, Seinfeld is calling ....
Rob=> Ok.. I'm off. Good night.

[Rob] leaves at Thu May 29 22:53:12 1997

wachsmut=> Talk to everybody later, then .... bye !!!!!
wachsmut=> Feel free to use this chat area any time you like, for your own
wachsmut=> discusssion, if you want ....
wachsmut=> Bye now .....

[wachsmut] leaves at Thu May 29 22:53:54 1997
[wachsmut] joins at Thu May 29 22:53:56 1997 from
[wachsmut] leaves at Thu May 29 22:54:00 1997
[wachsmut] joins at Thu May 29 22:54:03 1997 from
[David] leaves at Thu May 29 22:54:11 1997

wachsmut=> Your last chance to ask me anything ....

[wachsmut] leaves at Thu May 29 22:54:49 1997