Array stuff again...

[Rose Evans]

This is all I can figure out so far....

for (int enum = 1; enum <= numberOfEmployees; enum++)

Just totally lost!!

[Ray Stojonic]

with enum being a java keyword as of java 1.5, you should avoid using it as an variable identifier.

other than that, you're almost there.

an array has a length property, so:

for( int i = 0; i < array.length; ++i (or i++, makes no difference here) )

will iterate through an array named array.

Also, java arrays are zero based. If you had an array with 3 elements, they would be referred to as 0, 1, and 2.

The thought behind zero-based arrays can be summarized as referring to the beginning of each element in memory:

0       1       2       3
|element|element|element|

An array identifer refers to a location in memory, the sub refers to an offset from that location. Given an integer array integers, integers[3] says: "Please get the value of the 32 bits beginning at memory location x plus 3 times 32"

[Marcus Laubli]

Rose,

Read this, it will help you understand about arrays, and show you how to print, using your array.

Put a little more code together, we'll gladly help you !!

I did a search on Google for "Java Arrays", this was the second entry.

Marcus

[Rose Evans]

You guys, I am dumber than dirt....this is all I can come up with.

/**
Class for a one-week record of the time worked by
each employee. Uses a five-day week (Mon.-Fri.).
main has a sample application.
*/
public class TimeBook1
{
private int numberOfEmployees;
private int[][] hours;
// hours[i][j] has the hours for employee j on day i.
private int[] weekHours;
//weekHours[i] has the week's hours worked for
//employee i+1.
private int[] dayHours;
//dayHours[i] has the total hours worked by all
//employees on day i. Monday is 0, Tuesday 1, etc.


int i;

/**
Reads hours worked for each employee on each day of
the week into the two-dimensional array hours. (The method
for input is just a stub in this preliminary version.)
Computes the total weekly hours for each employee and
the total daily hours for all employees combined.
*/
public static void main(String[] args)
{
TimeBook1 book = new TimeBook1(3); //Creates a new object
book.setHours( ); //call methods
book.update( ); //call methods
book.showTable( );//call methods




}


public TimeBook1(int theNumberOfEmployees) // method---constructor
{
numberOfEmployees = theNumberOfEmployees;
hours = new int[5][numberOfEmployees]; //two dim. array 5 represents the days
//the 5 is for the 5 days Monday through Friday.
weekHours = new int[numberOfEmployees]; //constructor...size of array..number of employees
dayHours = new int[5];
}

public void setHours( ) //This is just a stub. Stub...not done yet.
{
for (int enum = 1; enum <= numberOfEmployees; enum++)




{



}



for (i = 0; i < 5; i++)
{

for (i = 0; i < 5; i++) //days? I think.
for(int i = 0; i<weekHours.length;i++)

{


}

}



// hours[0][0] = 8; hours[0][1] = 0; hours[0][2] = 9;
// hours[1][0] = 8; hours[1][1] = 0; hours[1][2] = 9;
// hours[2][0] = 8; hours[2][1] = 8; hours[2][2] = 8;
// hours[3][0] = 8; hours[3][1] = 8; hours[3][2] = 4;
// hours[4][0] = 8; hours[4][1] = 8; hours[4][2] = 8;
}

public void update( ) //method...calls 2 other methods computeWeekHours, and computeDayHours
{
computeWeekHours( );
computeDayHours( );
}

private void computeWeekHours( )
{
int dayNumber, employeeNumber, sum;

for (employeeNumber = 1;
employeeNumber <= numberOfEmployees; employeeNumber++)
{//Process one employee:
sum = 0;
for(dayNumber = 0; dayNumber < 5; dayNumber++)
sum = sum + hours[dayNumber][employeeNumber - 1];
//sum contains the sum of all the hours worked
//in one week by employee with number employeeNumber.
weekHours[employeeNumber - 1] = sum;
}
}

private void computeDayHours( )
{
int dayNumber, employeeNumber, sum;

for (dayNumber = 0; dayNumber < 5; dayNumber++)
{//Process one day (for all employees):
sum = 0;
for (employeeNumber = 1;
employeeNumber <= numberOfEmployees; employeeNumber++)
sum = sum + hours[dayNumber][employeeNumber - 1];
//sum contains the sum of all hours worked by all
//employees on day dayNumber.
dayHours[dayNumber] = sum;
}
}

public void showTable( )
{
int row, column;
System.out.print("Employee ");
for (column = 0; column < numberOfEmployees; column++)
System.out.print((column + 1) + " ");
System.out.println("Totals");
System.out.println( );

for (row = 0; row < 5; row++)
{
System.out.print(day(row) + " ");
for (column = 0; column < hours[row].length; column++)
System.out.print(hours[row][column] + " ");
System.out.println(dayHours[row]);
}
System.out.println( );

System.out.print("Total = ");
for (column = 0; column < numberOfEmployees; column++)
System.out.print(weekHours[column] + " ");
System.out.println( );
}

//Converts 0 to "Monday", 1 to "Tuesday" etc.
//Blanks used to make all strings the same length.
private String day(int dayNumber)
{
String dayName = null;
switch (dayNumber)
{
case 0:
dayName = "Monday ";
break;
case 1:
dayName = "Tuesday ";
break;
case 2:
dayName = "Wednesday";
break;
case 3:
dayName = "Thursday ";
break;
case 4:
dayName = "Friday ";
break;
default:
System.out.println("Fatal Error.");
System.exit(0);
break;
}

return dayName;
}

}

Sorry for pasting such a long code...somehow I gotta figure out how to get input from 3 employees, and then get input on how many hours they worked on Mon - Fri and then be able to show that in an array..the total hours they worked and stuff...any ideas??? I think my brain has turned to mush!!

[Marcus Laubli]

Rose, don't put yourself down like that. If you choose, you're entitled to be a child of the King. Why not?

There are a number of ways you can do this. Let's start with the weekdays array that doesn't change...

We'll continue with data input later. Here we go

  
public class TimeBook1 {
    
    static String [] weekdays =
    {
        "Sunday" , "Monday" , "Tuesday" , "Wednesday" , "Thursday" , 
"Friday" , "Saturday" 
    } ;
    
    public static void main(String [] args)
    {
    for ( int day = 0 ; day < weekdays.length ; day++ )
    {
System.out.println(  weekdays[ day ] ) ;
    }
    }
}

Run this, then tell me how and why it works.

In your attempt above, I see that you don't have anything down about how much of what you need. This has nothing to do with dumb or smar either.

You have to know what your deliverable requirements are. Here are a couple of questions:

1) How many empoloyees will there be?
2) Do we know their names, or do we have to enter them each time?
3) Will we have to enter hours for Bob, then print, then hours for Sally, then print, or will we have to enter everything, then print at the end?

See, this has tons to do with how you will design your program.

When you explain what my code did, also include the answers to the questions above, and make sure that you tell me about things you know that I didn't ask too!
[ January 27, 2005: Message edited by: Marcus Laubli ]

[Rose Evans]

Marcus,

Wow, you're smart!!! I ran your code and it prints out the days of the week like this.
Monday
Tuesday
Wednesday
and so on....

I get so confused with these statements.. for ( int day = 0 ; day < weekdays.length ; day++ )
___________________________________________________


Employee 1 2 3 Totals

Monday 0 0 0 0
Tuesday 0 0 0 0
Wednesday 0 0 0 0
Thursday 0 0 0 0
Friday 0 0 0 0

Total = 0 0 0

This is how my output is supposed to look...but I have no idea how to get the input in. I mean I'm supposed to ask a user to input three different employees hours that they worked each day.....
I don't know why this seems so hard to me..it should be easy.
Gotta go to math class soon...finite math...boy I'm terrible at that too. Ha..

[Marcus Laubli]

Rose,

Actually, it starts with Sunday!
What do you know about getting data from the screen. Can you teach me what you know? Which commands are you supposed to use for this exercise?
[ January 27, 2005: Message edited by: Marcus Laubli ]

[Rose Evans]

Marcus,

There are only 3 employees. We do not have to know their names, they are just called Employee 1, Employee 2, and Employee 3.

The output should be like this...

Employee 1 2 3 Totals

Monday 8 0 9 17
Tuesday 8 0 9 17
Wednesday 8 8 8 24
Thursday 8 8 4 20
Friday 8 8 8 24

Total = 40 24 38

Somehow I need to get input from the keyboard though, so like I can enter how many hours employee 1 worked on Monday, Tuesday, and so on.
I'm typing kinda fast...might not have answered all your questions on this post....just about late for math....I'll be back soon.
Thanks so much for your help!!!

[Rose Evans]

Marcus...by the way...you are one smart person!!! You must know java well!!! Are you a teacher? I like how you make me 'think' why the code is doing what its doing.

[Marcus Laubli]

 for ( int day = 0 ; day < weekdays.length ; day++ )
 

This is what's called a for loop (other languages call it a for - next loop).

Here's what it does:

1) int day creates an int variable called day.
2) day = 0 we're setting day to 0. This is where arrays start. Always.
3) ; actually means next statement
4) the middle statement is called the condition statement. In other words, while day < weekdays.length, keep on keepin' on!

Wait! What's weekdays.length? Now you need to know that each array has a property called length. It will tell you what it it's length is. This can get a little bit complicated. Don't get confused. Because the array is 0 based, we start counting 0 = Sunday, 1 = Monday, etc. This means that counting the "0 element", there are really 7 elements in the array. Count them! That's why we have day < weekdays.length!

Oh, one more thing.. this statement always has to test either true or false.

5) Now we have to say what to do if 4 doesn't test to true or false. In this case we add 1 to day. We could have said day + 1. The short way to do this in Java is day++.

That's it.

Now, before we go farther, tell me what is really happening here. You know what's going on in the loop, explain it to me please.

Actually, I've always enjoyed mentoring / tutoring, however, I'd love a job period right now!

I've been very ill for over 3 1/2 years. Bug bite fried my brain, lost 40% of my cognitive / memory. Guess God thought that I 1) either wasn't listening to Him, or 2) I was just getting too dangerous for my own good. That's when he decided to give me the headache of my life! Just getting back on my feet. Hope to find work soon.

I'll wait until you get back from class!
[ January 27, 2005: Message edited by: Marcus Laubli ]

[Rose Evans]

Marcus,,,

Where are you from? A bug bit you and made you sick?

[Layne Lund]

I agree with Marcus that you shouldn't put yourself down. Learning a new skill has little to do with how "smart" your are. It has A LOT to do with how much patience and perserverence you have, though. It looks like you are coming a long way with this program.

Personally, I am interested in your answers to Mark's questions. In particularly, can you explain in your own words what his short program does? Breaking it down like Mark did with the for statement is one way of doing this. Just try to explain it in your own words.

Good luck and Keep Coding!(TM)

Layne

[Marcus Laubli]

At that time, I was living in Southern Maryland, working as the webmaster and lead developer on the Lotus Notes / Domino platform in the Washington DC Jail. We suspect that I was bitten at work, but can't prove anything.

What happened was that I got encephalitis (an infection of the brain and spinal fluid), and the rest, as they say, is history.
[ January 27, 2005: Message edited by: Marcus Laubli ]

[Marcus Laubli]

Alright Layne... :roll:

Let bygones be bygones. I really made a typo!

I prefer Marcus.

[Rose Evans]

Marcus,

Well bless your heart!! Sounds like you've come a long way since then. I've heard of mosquito bites causing that to happen to people's brain if they get bitten. We usually have a ton of mosquitos here in SC...in the summer, and have to stay very protected.
You should come to SC for work, we are always needing great teachers for programming. Sounds like you would be excellent!!!
I'm heading out for the day...I just got back from lunch, and I do believe I don't feel like working any longer today. I only had one class today, math, and then I came to work. I think I'll go home and sleep for a few hours, then maybe this weekend, I'll tackle the answers to your questions.
)
I do appreciate your help very much!!! Thank you!!

[Rose Evans]

Layne,



I am going to try to study over those questions this weekend, and I'll see if I can answer them. I do feel like I am quite tired today. I was at work and school from 7:45 am to 9 pm last night, and I've been here all day too. I do believe I will retire for the day and go home and sleep.
Have a super weekend, and I'll keep chugging along with this programming.

[Rose Evans]

Marcus,,,,Oh by the way...that was supposed to be a smiley face I sent...not sure how that little red face got on there. Ha.

[marc weber]

Originally posted by Marcus Laubli:
At that time, I was living in Southern Maryland, working as the webmaster and lead developer on the Lotus Notes / Domino platform...

I would suspect Lotus Notes as the culprit, rather than a bug bite.

(I wish there was a NotesRanch!)

[Marcus Laubli]

I would suspect Lotus Notes as the culprit, rather than a bug bite.

Ouch! What just bit me!
[ January 27, 2005: Message edited by: Marcus Laubli ]

[Rose Evans]

OK am I showing my stupidity again.....you weren't really bitten by a bug ahahhahahahahaha....where is my brain....who stole it? I swear I used to have one...hahahahahahahha

[Rose Evans]

I think I have totally lost my mind hahahahahaha..

[Marcus Laubli]

Rose,

It really did happen. These guys are just being mean. Don't worry, I'll defend making a decent living with Lotus Notes!

Problem is, I'll probably take 5 years or more to make it up with Java if it's even possible.
[ January 27, 2005: Message edited by: Marcus Laubli ]

[marc weber]

Originally posted by Marcus Laubli:
...I'll defend making a decent living with Lotus Notes!

Actually, developing in Notes is the main part of my job. I suppose I shouldn't complain (having been at the same company for 10 years), but today is just a bad Notes day.
[ January 27, 2005: Message edited by: marc weber ]

[David Harkness]

Marcus, after seeing how you work with Rose in this thread, I think the main answer to your question in this other thread is that no matter what tools you choose to use for teaching your daughter programming, it's going to be smooth sailing all the way. Kudos to you!

Rose, as I'm telling a friend of mine taking Linear Algebra, keep positive and don't beat yourself down. If you let your spirit believe that you can't do something, your mind and body will make it happen because they don't like to be wrong.

Also, I've often found that if a student who is working hard to learn is having trouble learning, the first thing to suspect is the teacher and teaching methods. Consider one thing: you are very blessed to have resources like Java Ranch and the internet. When I was teaching myself to program BASIC on an Apple //e at age 11, I had no one to ask questions -- just a single book to start. Definitely keep taking advantage of the tools at hand!

One thing I try to do when learning a new concept is to put it into different terms. This allows me to not only understand it more deeply but also understand related concepts. With that said, here's the for loop translated into the equivalent while loop.

for ( <initialization> ; <condition> ; <iteration> ) {
    <loop-statements>
}
 
<initialization>
while ( <condition> ) {
    <loop-statements>
    <iteration>
}

Perhaps this will help you to better understand Marcus's sample program.

Oh, almost forgot: Notice that the array is called "weekdays" and the sample input/output does not include weekend days (though I typically work part of each weekend ).

[Rose Evans]

Marcus...so I haven't lost my mind...you did get bit by a bug?? Today, I think my brain has totally went on vacation!! I don't think I could add 2 + 2 today ahahahah...Thanks for all your messages, they sure have brightened my day.

[Rose Evans]

David,

Well you sound like a smart java guy too. Thanks for writing.

I learned Basic as well. I totally loved it, that was my first programming language, and I had the BEST teacher in the world. He knew it like the back of his hand, and he taught it well. I couldn't wait to go to class everyday, and I would spend hours, at home, just programming away until I figured out how to make it do what I wanted. I couldn't wait to go to that class each week!!!

I loved Visual Basic.NET too, it's fun making those GUI's...although the code can be quite drastic at times.
Didn't quite like C++, although I took two semesters of it. I like Java...but I guess I just get too confused with it all.

The Math, well I've never been a math person, some might ask what am I doing in programming then, seems math and programming go hand in hand.
I had to start out in the lower maths in college..surprising enough, I had never even taken alegbra in high school, so even that was new to me.

Didn't quite like my math teacher though, she wouldn't pay me a bit of attention in class, so I took that book home, and taught the entire book to myself! I ended up with a high B in the class, and I was pretty darn proud of myself. I wasn't going to let that class beat me. I took another math class after that....and got through it with a C hahahhah...that one was kinda tricky.... but this math...Finite math, with Matrix's and things like that, well whew...that's over my head. My teacher is so nice, but he doesn't speak English too well, I can understand him, but I can't understand his teaching, if that makes since. I'll just hang in there and see what I can do.
I think I've overloaded myself this semester, I've come so far though...supposed to graduate in July...but these darn maths are killing me!

Messages like yours are very uplifting...thanks a million.

[David Harkness]

Thanks! I think I'm pretty good at Java, too. And I'm really modest!

It's very difficult to learn something if it doesn't grab your interest. When I took the lower division calculus math classes, my heart wasn't in it. They were mildly interesting, but I had to plow through them. Even though I understood the material, I ended up with low B's and C's.

It wasn't until I got to the more advanced (challenging because they were complex, not hard because they were boring) I got high B's and mostly A's. Programming, though, has always been my passion. I think eventually I'd like to teach kids to program, but I think that's still some time off.

Yes, I very much enjoyed the language environments that let you build simple GUI apps. It felt like you were building a "serious application" in so few lines of code -- most of it by drawing on the screen! Maybe in fifty years we'll have languages advanced enough that doing complex server applications really will be like plugging components together. Heh, maybe 100 years.

Anyway, get some rest and I bet things will become a lot clearer for you.

[Marcus Laubli]

Rose, this is not self pitty. I confirm that I have been ill for 3 1/2 years, and that it was most likely a bug that bit me on my neck. This was about 2 PM in the afternoon on June 11, 2001. By 10 PM, I had a golf ball sized lump just a little further back than my right tonsil. That was the beginning of a very new and different part of my life.

Girl, you're on the home stretch. Go for gusto! Math? I always hated math. Never did anything more advanced than algebra. I flunked the NYS Algebra Regents exam with a 42% final score. Ouch!

Actually, things have changed some. Now that my mind is working again, I found this free book online to teach myself Digital Signal Processing. This is cool stuff.

While we're on the learning thing, I've been doing some serious brain exercises with a program that I found after my Doctor finally diagnosed me to have lost 40 % of both my cognitive and memory functionality (they compare it to your IQ and other things. Full recovery for me is possible, however, it will take between 5 and 8 years of daily therapy. It's so incredible, what the brain can do. I'm coming back and actually enjoying it.

By the way, I'm actually going to write the author of the book I mentionad above because he had this really cool article (you kidding, more like a dissertation) about mind / body functions. Why am I telling you this? Listen, if I can come around after this serious an illness, you can make it to the end of your semester. Keep chuggin. Even if it takes an extra semester, so what? In 10 years, no one will know the better.

David was right, just keep doing what you're doing. This too shall pass. If you want to go and get a Masters in Psychology, or a Doctorate in Under Water Basket Weaving later, you'll still have a four year degree under your belt.

Chin up, girl. Every time you think you're down, just start looking around. For sure, you'll find someone worse off than you. I have a blind friend who insists that she's not disabled, she just doen't have as many advantages as I do. Another blind friend is the main switchboard operator at the main Red Cross offices in Geneva, Switzerland. Have another friend who just had a major portion of her large intestines removed this last week. I could go on, but suffice it to say, we've got it good.

Go think about what your code is supposed to do, and we'll talk on Monday. I'm not promising you anything, but you have so much expertise available to you on this website that you could learn more in just this one exercise than in a semester of going to class. Let's see where it leads us!
[ January 27, 2005: Message edited by: Marcus Laubli ]

[Rose Evans]

Marcus...I'll be back very soon. Not working today...I feel kinda sick. I think I'm gonna lay my little self down on my bed and rest for a few hours today. I'll surely tackle the java stuff after I wake up.

[Rose Evans]

David, I'll write ya back very soon. I'm sure you can see from my last post, I am totally under the weather today. I'm gonna sleep for a few hours, maybe more. Ha. Took the day off from work, and I'm gonna rest, rest, rest.
Hope you have a wonderful day!

[Rose Evans]

Oh yeah, just curious...when I signed up at this java ranch I was a greenhorn or something like that, now I'm a ranch hand, how'd I do that? Hahahahahah...I think I like being a ranch hand better than a green horn ahhahahaahah...Sounds better anyway.

[David Harkness]

Originally posted by Rose Evans:
Oh yeah, just curious...when I signed up at this java ranch I was a greenhorn or something like that, now I'm a ranch hand, how'd I do that?

The FAQ is throwing exceptions at the moment, so I'll just have to guess. I believe it's solely based on your total number of posts. Seeing as you are at 118, it probably promoted you to Ranch Hand at 100. Didn't you get your free case of beer?

Rest up. I hope you feel better. I know that when I cut back on sleep I get the same way. Sleep isn't like chocolate -- your body actually needs sleep. Oh wait . . . it is just like chocolate!

[Rose Evans]

David,

Hahhah you are too funny. No, I didn't get my free case of beer, hum, maybe I should request that I do. Ha.
I just wondered how I went from a greenhorn to a ranch hand...somehow a green horn just doesn't sound too pleasant for a lady ahahhahahahah...
I'm feeling a tad better now, been in bed just about all day. Still too tired to tackle any homework though. Guess that'll have to wait till tomorrow. Can't study 24/7, that wouldn't be too fun, would it?
Talk to you soon.

[Rose Evans]

Marcus,

Well bless your heart! I truly am sorry to hear that you have went through so much. Oh by the way, June 11th is my birthday, hum?

By reading your post, you don't seem to have lost anything! You seem to be so smart and so intelligent!! (I guess I spelled that word right)Ha.

I was just reading in my psychology book about the brain's plasticity...and how it can recover from some of the worst injuries. Matter of fact, I chose to answer a discussion question on that topic.
It seems the brain can rewire itself somehow, it was a really fascinating thing to learn.

You sound like such an upbeat person, and you seem to have the best outlook on life! I truly hope you can achieve all that you desire in your life.

Talk to you soon. I'm still trying to recover myself today...feeling a tad better, but not good enough to sit and do homework.

[Marcus Laubli]

Rose,

The re-wiring is exactly what my daily therapy is doing.

Looking forward to what you come up with on Monday! Take your time and rest.

BTW, when do you have to hand this in?

[Junilu Lacar]

Originally posted by David Harkness:
I believe it's solely based on your total number of posts. Seeing as you are at 118, it probably promoted you to Ranch Hand at 100. Didn't you get your free case of beer?

Any bartender worth his salt has to know that greenhorns automagically turn into ranch hands after their 30th drink. BTW, we serve whiskey Beer is for tailgaters.
[ January 29, 2005: Message edited by: Junilu Lacar ]

[Rose Evans]

Marcus, it was due last Wednesday. Pout...I don't know how many points I'll get taken off for it being late...shoot.
I have really bogged myself down with five classes this semester and each take hours of study. Just my psychology class, oh my goodness, the chapters are long, and complicated, and he tests us on chapter one, two, and three, and then all three together, and then we have to answer three discussion questions..And I have four other classes that I really have to 'study' for....so I'm in a bind. My main priority is my programming languages, and its hard to focus on that when I'm having to spend so much time with those other nonsense courses...like accounting. Ha.
I'm still feeling a little sick, stayed in bed all day yesterday too, and I haven't opened a book this weekend. I feel bad about that but I just don't feel like studying. Plus it snowed here yesterday, and it's all icy outside....I'm ready for summer time.

[Rose Evans]

Junilu, Ha ha...well pass the whiskey then. I see you're a bartender, you must have really drank a lot to get to that title. Hahahhaahhaha...Cheers to you.

[Layne Lund]

Originally posted by Marcus Laubli:
Alright Layne... :roll:

Let bygones be bygones. I really made a typo!

I prefer Marcus.

Doh! Sorry about the typo! I guess that makes us even.

[Rose Evans]

Marcus....are ya still out there and kicking??
I'm bouncing back from being sick, and I'm just about ready to java again ahhahahah...gotta catch up on two psychology test, and some accounting homework first though.
Hope you're doing ok.