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The Big Programming Thread - Page 395

Forum Index > General Forum
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Thread Rules
1. This is not a "do my homework for me" thread. If you have specific questions, ask, but don't post an assignment or homework problem and expect an exact solution.
2. No recruiting for your cockamamie projects (you won't replace facebook with 3 dudes you found on the internet and $20)
3. If you can't articulate why a language is bad, don't start slinging shit about it. Just remember that nothing is worse than making CSS IE6 compatible.
4. Use [code] tags to format code blocks.
CatNzHat
Profile Blog Joined February 2011
United States1599 Posts
November 18 2013 02:16 GMT
#7881
On November 18 2013 10:44 FunkyLich wrote:
Show nested quote +
On November 17 2013 12:06 Housemd wrote:
Ok guys, I'm a complete newbie so please bear with me. I'm also not sure if this is allowed but here goes nothing.

The task is to write Java code using a for statement to sum the numbers from 1 through 50.

This is what I have so far:

int sum = 0;
for (int y = 0; y<=50; y++);
{
sum = sum + y;
}
System.out.println(sum);


Now, the problem is that Eclipse keeps on saying "y" is an unresolved variable. I just can't understand it. I have declared y in my for loop and while searching online, I saw the same thing. I need to get through this problem to make sure my sum is correct so if someone could please point out my mistake, it would be a big help.


So it sounds like you found the problem with the semicolon. I just wanted to point out something I would consider a mistake. Your for loop took y from 0 to 50 instead of 1 to 50. I'm not trying to be nit picky. I understand it produces the same result; I just wanted to make sure you were not being careless. When programming loops, it can get very tricky to think about all the plus ones and minus ones. I've been doing this for a while and the nuances of inclusive/exclusive addition still get me.

As they say, there are only 2 hard things in Computer Science, caching, naming things, and off-by-1 errors.
dae
Profile Joined June 2010
Canada1600 Posts
November 18 2013 03:04 GMT
#7882
On November 18 2013 11:16 CatNzHat wrote:
Show nested quote +
On November 18 2013 10:44 FunkyLich wrote:
On November 17 2013 12:06 Housemd wrote:
Ok guys, I'm a complete newbie so please bear with me. I'm also not sure if this is allowed but here goes nothing.

The task is to write Java code using a for statement to sum the numbers from 1 through 50.

This is what I have so far:

int sum = 0;
for (int y = 0; y<=50; y++);
{
sum = sum + y;
}
System.out.println(sum);


Now, the problem is that Eclipse keeps on saying "y" is an unresolved variable. I just can't understand it. I have declared y in my for loop and while searching online, I saw the same thing. I need to get through this problem to make sure my sum is correct so if someone could please point out my mistake, it would be a big help.


So it sounds like you found the problem with the semicolon. I just wanted to point out something I would consider a mistake. Your for loop took y from 0 to 50 instead of 1 to 50. I'm not trying to be nit picky. I understand it produces the same result; I just wanted to make sure you were not being careless. When programming loops, it can get very tricky to think about all the plus ones and minus ones. I've been doing this for a while and the nuances of inclusive/exclusive addition still get me.

As they say, there are only 2 hard things in Computer Science, caching, naming things, and off-by-1 errors.


God, finding a nice naming convention is so hard >.<.

I tend to just vary alot depending how I feel on that day, which for schoolwork is fine but whenever I work on larger projects it tends to get all over the place.
scudst0rm
Profile Joined May 2010
Canada1149 Posts
November 18 2013 04:52 GMT
#7883
On November 18 2013 11:16 CatNzHat wrote:
Show nested quote +
On November 18 2013 10:44 FunkyLich wrote:
On November 17 2013 12:06 Housemd wrote:
Ok guys, I'm a complete newbie so please bear with me. I'm also not sure if this is allowed but here goes nothing.

The task is to write Java code using a for statement to sum the numbers from 1 through 50.

This is what I have so far:

int sum = 0;
for (int y = 0; y<=50; y++);
{
sum = sum + y;
}
System.out.println(sum);


Now, the problem is that Eclipse keeps on saying "y" is an unresolved variable. I just can't understand it. I have declared y in my for loop and while searching online, I saw the same thing. I need to get through this problem to make sure my sum is correct so if someone could please point out my mistake, it would be a big help.


So it sounds like you found the problem with the semicolon. I just wanted to point out something I would consider a mistake. Your for loop took y from 0 to 50 instead of 1 to 50. I'm not trying to be nit picky. I understand it produces the same result; I just wanted to make sure you were not being careless. When programming loops, it can get very tricky to think about all the plus ones and minus ones. I've been doing this for a while and the nuances of inclusive/exclusive addition still get me.

As they say, there are only 2 hard things in Computer Science, caching, naming things, and off-by-1 errors.


lol. They also claim that there are 10 types of people.
You're like a one ranger army comin' at me...
WolfintheSheep
Profile Joined June 2011
Canada14127 Posts
November 18 2013 05:33 GMT
#7884
On November 18 2013 13:52 scudst0rm wrote:
Show nested quote +
On November 18 2013 11:16 CatNzHat wrote:
On November 18 2013 10:44 FunkyLich wrote:
On November 17 2013 12:06 Housemd wrote:
Ok guys, I'm a complete newbie so please bear with me. I'm also not sure if this is allowed but here goes nothing.

The task is to write Java code using a for statement to sum the numbers from 1 through 50.

This is what I have so far:

int sum = 0;
for (int y = 0; y<=50; y++);
{
sum = sum + y;
}
System.out.println(sum);


Now, the problem is that Eclipse keeps on saying "y" is an unresolved variable. I just can't understand it. I have declared y in my for loop and while searching online, I saw the same thing. I need to get through this problem to make sure my sum is correct so if someone could please point out my mistake, it would be a big help.


So it sounds like you found the problem with the semicolon. I just wanted to point out something I would consider a mistake. Your for loop took y from 0 to 50 instead of 1 to 50. I'm not trying to be nit picky. I understand it produces the same result; I just wanted to make sure you were not being careless. When programming loops, it can get very tricky to think about all the plus ones and minus ones. I've been doing this for a while and the nuances of inclusive/exclusive addition still get me.

As they say, there are only 2 hard things in Computer Science, caching, naming things, and off-by-1 errors.


lol. They also claim that there are 10 types of people.


We're up to 10 now? Last I heard it was 0F.
Average means I'm better than half of you.
sluggaslamoo
Profile Blog Joined November 2009
Australia4494 Posts
Last Edited: 2013-11-18 07:02:06
November 18 2013 07:00 GMT
#7885
On November 17 2013 14:25 CatNzHat wrote:
Show nested quote +
On November 16 2013 17:02 FakePseudo wrote:
Hi guys,

So I've been using git for more then a year now, and I'm starting to go a bit beyond the basics, as I have to maintain several repos for some groups assignment where most users are really inexperimented (with git I mean). However, one thing still bothers me: what is your easiest and fastest way to apply changes across all branches (like a .gitignore change or w/e makes sense to you) that does not involve git push force right after it (so no rewinding history to a common ancestor or other weird rebasing)? For the time being I use cherry-picking or merging but it really isn't efficient nor meaningful for anyone reading the git log or tree, but I figure there should be a better way...(googling and all didnt help much)


I work at a company with an engineering team of about 16 and we keep all branches up to date with production by automatically merging master in after every successful deploy. If you could explain a bit more about why you want to apply a change across all branches that would be helpful. Usually you'd just branch off master and then make a pull request into master, and then everyone would have that change if they're keeping their branch up to date with master. They could resolve any conflicts themselves, or if they didn't want to deal with that they could just let their branch fall behind master and then you could handle the merge while processing their pull request.

It seems to me like this problem is occuring because you're all committing to branches and merging them yourselves instead of making pull requests to merge your feature branch into master or an appropriate integration branch.

One of the biggest benefits of working with a group of people on a project is having your code reviewed by someone else. They don't' have to be more experienced than you, or even understand all of your code, just having a second set of eyes makes a huge difference. Get into the habit of making pull requests, assigning them to someone, getting feedback, and iterating. This helps everyone enforce good programming habits, and it makes it easier for you to stray outside your comfort zone, knowing that you can get someone who knows more about what you're trying to accomplish to look over your code and help you make it the best it can be.

Good luck with Git!


Pull request are a little difficult without Github though. but I completely 100% agree with this, the main issue will be getting people motivated to do pull requests. Its easy to do in a team that loves to do them, but if the manager doesn't wanna do it none of his employees will bother either.

Also if you are using the right "branch layout" you should never run into this problem.

Basically you should have a branch for each version (0.1, 0.2, etc) that you treat like your master branch, NEVER PUSH TO MASTER!!! If you want to know more have a look at "Continous Delivery" by Humble and Farley.
Come play Android Netrunner - http://www.teamliquid.net/forum/viewmessage.php?topic_id=409008
sluggaslamoo
Profile Blog Joined November 2009
Australia4494 Posts
Last Edited: 2013-11-18 07:13:09
November 18 2013 07:10 GMT
#7886
On November 18 2013 12:04 dae wrote:
Show nested quote +
On November 18 2013 11:16 CatNzHat wrote:
On November 18 2013 10:44 FunkyLich wrote:
On November 17 2013 12:06 Housemd wrote:
Ok guys, I'm a complete newbie so please bear with me. I'm also not sure if this is allowed but here goes nothing.

The task is to write Java code using a for statement to sum the numbers from 1 through 50.

This is what I have so far:

int sum = 0;
for (int y = 0; y<=50; y++);
{
sum = sum + y;
}
System.out.println(sum);


Now, the problem is that Eclipse keeps on saying "y" is an unresolved variable. I just can't understand it. I have declared y in my for loop and while searching online, I saw the same thing. I need to get through this problem to make sure my sum is correct so if someone could please point out my mistake, it would be a big help.


So it sounds like you found the problem with the semicolon. I just wanted to point out something I would consider a mistake. Your for loop took y from 0 to 50 instead of 1 to 50. I'm not trying to be nit picky. I understand it produces the same result; I just wanted to make sure you were not being careless. When programming loops, it can get very tricky to think about all the plus ones and minus ones. I've been doing this for a while and the nuances of inclusive/exclusive addition still get me.

As they say, there are only 2 hard things in Computer Science, caching, naming things, and off-by-1 errors.


God, finding a nice naming convention is so hard >.<.

I tend to just vary alot depending how I feel on that day, which for schoolwork is fine but whenever I work on larger projects it tends to get all over the place.


I used to have a very hard time naming things until I stopped using the internet for information and started reading books. I read through 10+ OOP books in about 6 months and afterwards I never had a problem designing classes let alone naming them. These days I think up multiple classes and names and figure out how to interact them within seconds before I even start. :D

The internet is great for examples, but not a lot of people want to learn the fundamentals which leaves those websites at the bottom ranking, or there just aren't a lot of them because most people are simply not interested.

Usually everything falls into a certain subtype which makes naming very easy. You will never find this information on the internet though, you have to dig through books.

Rather than tell you how to do any of this, because it seems that whenever I give advice someone finds a reason to flame me, so Ill just list some books that really helped me and I'm sure will help you.

The gang of four design patterns book will help you understand what subtype your classifications (classes) fall into.

http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612

Object Design by Wirfs Brock and Mckeen will help you understand roles and responsibilities which help you to name more obtuse class designs and interactions.

http://www.amazon.com/Object-Design-Roles-Responsibilities-Collaborations/dp/0201379430

Clean Code by Robert C Martin will help you to understand functional decomposition. Making your functions atomic so that your classes remain readable from the inside out.

http://www.amazon.com/Clean-Code-Handbook-Software-Craftsmanship/dp/0132350882
Come play Android Netrunner - http://www.teamliquid.net/forum/viewmessage.php?topic_id=409008
Manit0u
Profile Blog Joined August 2004
Poland17865 Posts
November 18 2013 09:28 GMT
#7887
Question: Are there any good IDEs for C# outside of Visual Studio? (don't want to spend a ton of money before I'm certain I can and want to fully commit to it).
Time is precious. Waste it wisely.
Arnstein
Profile Blog Joined May 2010
Norway3381 Posts
November 18 2013 10:06 GMT
#7888
Any reason why you wouldn't use Vim or Emacs?
rsol in response to the dragoon voice being heard in SCII: dragoon ai reaches new lows: wanders into wrong game
ObviousOne
Profile Joined April 2012
United States3704 Posts
November 18 2013 10:21 GMT
#7889
On November 18 2013 18:28 Manit0u wrote:
Question: Are there any good IDEs for C# outside of Visual Studio? (don't want to spend a ton of money before I'm certain I can and want to fully commit to it).

You can use VS Express if you have a hotmail/live/msn account to "try" it. Fairly limited, though and I've learned nothing about building projects since it does all of that for you (after you google a tutorial to figure that out). Start the hard way, with a basic editor and compiler and go from there, IMO. Really the only part of VS that I like is the intellisense/autocomplete.

Notepad++ for instance since it does highlighting, and whatever compiler for your OS.
Fear is the only darkness. ~Destiny Fan Club operator~
Manit0u
Profile Blog Joined August 2004
Poland17865 Posts
November 18 2013 10:56 GMT
#7890
Oh, OK then. I thought that you'd be at some serious disadvantage when not using VS

This is even better.
Time is precious. Waste it wisely.
WindWolf
Profile Blog Joined July 2012
Sweden11767 Posts
November 18 2013 11:16 GMT
#7891
While we are talking about VS.

Has anyone here had a chance to touch VS 2013 yet? How much different is it compared to VS2012? I'm primary wondering about the C++ side of things. (I'm gonna stick with 2012 for a while, since that is what my teacher will use in the upcoming courses at university, but I'm still curious)
EZ4ENCE
bangsholt
Profile Joined June 2011
Denmark138 Posts
November 18 2013 13:13 GMT
#7892
On November 18 2013 18:28 Manit0u wrote:
Question: Are there any good IDEs for C# outside of Visual Studio? (don't want to spend a ton of money before I'm certain I can and want to fully commit to it).


http://monodevelop.com/
sluggaslamoo
Profile Blog Joined November 2009
Australia4494 Posts
November 18 2013 13:41 GMT
#7893
On November 18 2013 19:21 ObviousOne wrote:
Show nested quote +
On November 18 2013 18:28 Manit0u wrote:
Question: Are there any good IDEs for C# outside of Visual Studio? (don't want to spend a ton of money before I'm certain I can and want to fully commit to it).

You can use VS Express if you have a hotmail/live/msn account to "try" it. Fairly limited, though and I've learned nothing about building projects since it does all of that for you (after you google a tutorial to figure that out). Start the hard way, with a basic editor and compiler and go from there, IMO. Really the only part of VS that I like is the intellisense/autocomplete.

Notepad++ for instance since it does highlighting, and whatever compiler for your OS.


In my experience I could pretty much do everything I needed to do in VS Express, theres an Indie online RPG engine written in VS Express.

http://www.netgore.com/

Unless you're doing an enterprise app or something, I don't think it would be a problem.
Come play Android Netrunner - http://www.teamliquid.net/forum/viewmessage.php?topic_id=409008
patermatrix
Profile Joined March 2012
64 Posts
Last Edited: 2013-11-18 13:54:27
November 18 2013 13:53 GMT
#7894
On November 18 2013 19:56 Manit0u wrote:
Oh, OK then. I thought that you'd be at some serious disadvantage when not using VS

You are.

Vim, emacs, Notepad++, they're all decent to excellent code editors when you work within a single file. As soon as you start working on projects, you won't want to miss features like autocomplete and refactoring which only a real IDE can provide. And not to mention that VS probably has the best debugging features out of all IDEs.

VS Express should be enough for most things though, so don't bother paying unless you really need something only the full versions can offer.
Rollin
Profile Joined March 2011
Australia1552 Posts
Last Edited: 2013-11-18 14:08:33
November 18 2013 14:07 GMT
#7895
On November 18 2013 22:41 sluggaslamoo wrote:
Show nested quote +
On November 18 2013 19:21 ObviousOne wrote:
On November 18 2013 18:28 Manit0u wrote:
Question: Are there any good IDEs for C# outside of Visual Studio? (don't want to spend a ton of money before I'm certain I can and want to fully commit to it).

You can use VS Express if you have a hotmail/live/msn account to "try" it. Fairly limited, though and I've learned nothing about building projects since it does all of that for you (after you google a tutorial to figure that out). Start the hard way, with a basic editor and compiler and go from there, IMO. Really the only part of VS that I like is the intellisense/autocomplete.

Notepad++ for instance since it does highlighting, and whatever compiler for your OS.


In my experience I could pretty much do everything I needed to do in VS Express, theres an Indie online RPG engine written in VS Express.

http://www.netgore.com/

Unless you're doing an enterprise app or something, I don't think it would be a problem.

Imho the biggest disadvantage of express is the lack of support for user extensions, like visual assist x, but I don't even use them lol. There are probably other things too.

On November 18 2013 20:16 WindWolf wrote:
While we are talking about VS.

Has anyone here had a chance to touch VS 2013 yet? How much different is it compared to VS2012? I'm primary wondering about the C++ side of things. (I'm gonna stick with 2012 for a while, since that is what my teacher will use in the upcoming courses at university, but I'm still curious)

Well I only got it today , but so far:
- Better, but still not complete, c++11 support
- Better syntax highlighting, though still not great
- I like the layout more than 2012, which was shit imo

I am a noob though and I've barely played with it . But for free, I'd say it was worth the upgrade.
Throw off those chains of reason, and your prison disappears. | Check your posting frequency timeline: http://www.teamliquid.net/mytlnet/post_activity_img.php
Shield
Profile Blog Joined August 2009
Bulgaria4824 Posts
November 18 2013 14:29 GMT
#7896
Amount £0.00

Microsoft Visual Studio Professional 2013 32-bit (English) - DreamSpark - Download
Extended Access Guarantee (24 months) Extended Access Guarantee (24 months) - Included
24 months of access to your download and/or key. This does not extend the duration of time-limited licenses (if applicable).
Expires 2015-11-18
Messages:

DreamSpark EULA


Gotta love to be a student from a Computer Science department. I'm downloading it even though I use Java for my project, so Eclipse is what matters for me now.
Manit0u
Profile Blog Joined August 2004
Poland17865 Posts
Last Edited: 2013-11-18 15:24:24
November 18 2013 14:32 GMT
#7897
For Java I would use NetBeans. Worked much better for me than Eclipse ever did.

Edit: Also,

On November 13 2013 06:57 EscPlan9 wrote:
Really should just initialize the loop variable inside the loops. Cleans up the code a bunch:


#include <stdio.h>

int main()
{
int array[10][10];
int count;

for ( int i = 0; i<10; ++i )
{
for (int j = 0; j<10; ++j )
{
array[i][j] = count;
count++;
}
}

for (int i = 0; i<10; ++i )
{
for (int j = 0; j<10; ++j )
{
printf( "%d", array[i][j] );
printf( " " );
}
printf("\n");

}
}




I don't think you should be using "++i" statements for incrementation in a for loop. I'm of the opinion that they did a great job in Python with eliminating the ++ and -- operators (both pre- and post-) and leaving just += and -=. So much more consistent.
Time is precious. Waste it wisely.
WindWolf
Profile Blog Joined July 2012
Sweden11767 Posts
November 18 2013 14:32 GMT
#7898
On November 18 2013 23:07 Rollin wrote:
Show nested quote +
On November 18 2013 20:16 WindWolf wrote:
While we are talking about VS.

Has anyone here had a chance to touch VS 2013 yet? How much different is it compared to VS2012? I'm primary wondering about the C++ side of things. (I'm gonna stick with 2012 for a while, since that is what my teacher will use in the upcoming courses at university, but I'm still curious)

Well I only got it today , but so far:
- Better, but still not complete, c++11 support
- Better syntax highlighting, though still not great
- I like the layout more than 2012, which was shit imo

I am a noob though and I've barely played with it . But for free, I'd say it was worth the upgrade.

I still waiting a bit with upgrading since I'm using Boost quite a bit and the latest release had some problems with VS 2013.
EZ4ENCE
mcc
Profile Joined October 2010
Czech Republic4646 Posts
November 18 2013 16:14 GMT
#7899
On November 17 2013 05:24 Morfildur wrote:
Show nested quote +
On November 16 2013 17:29 obesechicken13 wrote:
On November 16 2013 16:17 ObviousOne wrote:
On November 16 2013 15:22 obesechicken13 wrote:
On November 16 2013 13:38 ObviousOne wrote:
Bid is linked to a user and an item and has an amount. Doesn't that qualify as a strong entity?

Bid table:
PK- bid id
FK- user id
FK- item id
bid amount

No? Been ages since I had this class.

That would qualify, and that's what I'm thinking of doing just so I'll have a strong entity, but then what's the point of calling them foreign keys? Isn't this overly complicated?

FK reienforces relationships, right? You want to make sure there are no bids without corresponding items or users, so you get referential integrity or w/e the word is.

bid_id user_id item_id bid_amount
1 101 1001 999.99
2 105 1001 1499.99
3 101 1001 1999.99

You can then look up all bids from X person on Y item. You never want a situation where the user_id or item_id is invalid. This gives you bid history and a query can give you the max bid based on item to find the winner or whatever other business goals you might have.

The DBMS enforces the relationships for you, I think is the purpose of calling it a FK.

Alright thank you. I wasn't even sure if an entity could have a foreign key and primary key in the same setting. I think I've tried it out in code but I was getting some errors whenever I did anything with foreign keys. That's why I couldn't just try to have a primary key and foreign key together.

I still don't know if this is a best practice but it's what the professor wants.


There is a common problem people run into when they start to use foreign keys and from the sound of it, you encountered it as well:
Foreign keys are in the database scope, meaning you can't use two equally named foreign keys, even if they are in different tables. They always have to have a unique name. MySQL has horrible error messages which really never explain the actual problem, so it's possible you tried to use two equally named foreign keys when you tried to use a primary and foreign key together.

Show nested quote +
On November 16 2013 13:17 obesechicken13 wrote:
My professor said we weren't supposed to use weak entities. This is bugging me.

Like my assignment is to draw out an ERD. It sounds simple but not having any weak entities just seems like unnecessary complexity to a system.

Eg my system has users
It also has items
and it has bids

the bids table might not have bid ids. I might want that to be a weak entity. What's wrong with that?
I guess if I delete the user or the item the bid will disappear too, but if my item disappears or the user does, don't I want the bid to disappear?


There are lots of situations where, even when the item it relates to is deleted, you want to keep the entry. As a simple example, think of a message board. If you delete a user, you still want the posts to remain so the discussion stays consistent and doesn't suddenly have holes. For bids, yes, you'd probably want them to disappear. It always depends on the program.

Though even in the message board example, I would probably add is_active (or similar) column on the user table, instead of actually removing the record physically, just to be able to keep all the data consistently referenced. I see very few reasons to ever remove rows from core tables.
mcc
Profile Joined October 2010
Czech Republic4646 Posts
November 18 2013 16:21 GMT
#7900
On November 18 2013 18:28 Manit0u wrote:
Question: Are there any good IDEs for C# outside of Visual Studio? (don't want to spend a ton of money before I'm certain I can and want to fully commit to it).

You want , there might be good IDEs, but none as good as VS. There are also free versions that are somewhat functional I think, but I am not sure about that.
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