Does not Developers get confused if there are too many global variables?

[Mohammed Hameed]

Thanks :)

Understand SOLID! Believe SOLID! Try SOLID; your Code becomes Rock SOLID!!!

[Lost User]

Not that I am particularly defending the use of var, but I quite like it in the case of

var foo = new SomeReallyQuiteSensibleButLongName();

especially if there are a few of them (cuz they line up and look nice) You can see what the type is easily, so no harm done. When it is

var foo = TheResultOfSomeFunctionWhoseNAmeDoesntReflectItsReturnType();

it annoys me as I have to use intellisense to ind out what type it is. Especially annoying with something like

var selectedCustomer = GetCustomerFromList();

which, at first glance, I would guess at selectedCustomer being some kind of Customer object. Imagine my surprise when I find out it is a boolean! Yep - the function returns a boolean that determines whether the customer was selected from the list. Now this comes down to good naming - and I have yet to meet a developer that names consistently well (myself included)

MVVM # - I did it My Way ___________________________________________ Man, you're a god. - walterhevedeich 26/05/2011 .\\axxx (That's an 'M')

[Roger Wright]

It's a lot nicer than the old VBS, though. :-D

Will Rogers never met me.

[Roger Wright]

Back in the day, global variables were the only kind we had, and sometimes we had to re-use them. ;P Some of us are still coding... :-O

Will Rogers never met me.

[realJSOP]

Define "too many". I use whatever gets the job done. And what does "global" mean anymore? In .Net, everything's in a class. I often employ a static class that I call "Globals". Most of the contents are methods, but a lot of times, there's a collection or two in it.

".45 ACP - because shooting twice is just silly" - JSOP, 2010
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You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
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"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass." - Dale Earnhardt, 1997

[Lost User]

OK, I was probably confusing "Global" with "static public". I just assumed they were synonyms. It's been some years since using anything but C#. I do from time to time use static public when a variable needs to be accessed from multiple classes. I assume the jury is less likely to convict me for this crime? :confused: I am a self-taught programmer working on my own - no one else to ask. This is why this forum is of crucial importance to me.

[Nish Nishant]

John Simmons / outlaw programmer wrote:

And what does "global" mean anymore? In .Net, everything's in a class.

Some people still work on C/C++ :-)

Regards, Nish

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Blog: voidnish.wordpress.com The life of a Malayalee American - by Nish

An article I recently wrote for an event souvenir

[Mohammed Hameed]

Thanks Nish for mentioning about C/C++ also.

Understand SOLID! Believe SOLID! Try SOLID; your Code becomes Rock SOLID!!!

[Mycroft Holmes]

We also use a minimum of public statics but for fucks sake stick them all in the one place. Public statics scattered throughout the app is a sure sign on incompetence.

Never underestimate the power of human stupidity RAH

[Lost User]

Yeah, I usually create a small static class to hold all the static vars.

[Lost User]

Yeah, I usually put them all in a small, dedicated static class. Seems to work well for me.

[R Erasmus]

Agree, they should read up on data coupling a bit.

"Program testing can be used to show the presence of bugs, but never to show their absence." << please vote!! >>

[Stefan_Lang]

OriginalGriff wrote:

I'm just glad var is shorter and easier to type than dynamic

If differences in typing speed is your most pressing problem, get an editor where it isn't (hint: language sensitive autocompletion helps).

[Stefan_Lang]

I've found that some people prefer defining globals, or defining variables within too wide a scope just for the sake of not having to pass them as a parameter to a function, because that would require typing additional parameters. Sadly, even language-sensitive editors cannot help a lot with this. Still, additional typing should never affect your coding design decisions! For example I've seen classes with lots of private member variables that are really only required to hold temporary flags and states of operations, rather than indicate the actual state of the object. I consider that almost as bad as using globals. I know I like declaring globals or class members instead of local vars when prototyping new code when I'm not yet sure about the final design. But, even if I often don't clean up my code to the degree I should, at the very least I'll move my variables to the proper scope. It's the minimum I can do to keep my interfaces clean.

[Rob Grainger]

Actually, public statics are nearly as bad. The crucial factor here is that they can introduce problems in the presence of concurrency - if two tasks/threads/... attempt to update the same global/static, the state of the system becomes indeterminate. Singletons are frequently referred to as an anti-pattern for exactly this reason. All such rules are made to be broken, however, and I sometimes have to use public statics - to avoid passing some variable references absolutely everywhere (because most languages don't have good support for lexical scoping). But I do think about each and every such useful very carefully and prefer to find alternatives.

"If you don't fail at least 90 percent of the time, you're not aiming high enough." Alan Kay.

[Rob Grainger]

That's one big problem, I've seen many projects like this (especially in VB6). The list of globals has a tendency to grow, never to shrink. Cleaning (or even understanding) such programs is an exercise in frustration.

"If you don't fail at least 90 percent of the time, you're not aiming high enough." Alan Kay.

[StatementTerminator]

It's simple really: variables should be visible only where they need to be, which means the scope should be as limited as possible. There are lots of reasons for this, including the fact that some of the worst bugs in the world are caused by using variables with too wide of a scope. I once saw a daily import of very important financial data blow up due to such a bug. The guy who wrote the import routine in T-SQL read the identity of the last inserted record of a certain table using @@IDENTITY. This was important because if it got the wrong identity back foreign keys would get all screwed up during the import. Anyway, guess what happened when another developer innocently added a trigger to the table for bulk imports? Yeah. @@IDENTITY is essentially global in scope, so adding an insert trigger to the table--which should have been fine--blew it the hell up. That ended up costing a good chunk of real money for the company. It was also a hard one to debug, because the trigger was the only new code and everyone looked over it and it looked fine, it took a while to figure out what was happening with the import routine which had been in production for years. And all because @@IDENTITY was used instead of SCOPE_IDENTITY. There are very few cases where global variables are a good idea. They make good time bombs though.

[GenJerDan]

Rob Grainger wrote:

Actually, public statics are nearly as bad. The crucial factor here is that they can introduce problems in the presence of concurrency - if two tasks/threads/... attempt to update the same global/static, the state of the system becomes indeterminate.

Yeah, I hate it when a program ignores what I've written and starts doing things on its own.

YouTube and My Mu[sic], Films and Windows Programs, etc.

[patbob]

I see people use global variables (and class statics, and sometimes singletons) when they don't want to think too hard about how, and where, it will need to be accessed. Confusion? Yeah. Discomfort? Those who use them a lot, get used to keeping track of their scope of use manually.. and once you get into that style of coding, more aren't necessarily much worse. Conveying that scope of use information to the next programmer is difficult, and very quickly the code ends up on a toboggan ride to a very warm place. Unless they're used to hold immutable data that's set up very early in the program, they're usually a maintenance nightmare.

We can program with only 1's, but if all you've got are zeros, you've got nothing.

[RafagaX]

If your program uses global variables, they tend to grow over time, given that every new person that comes next will introduce their own (often redundant) global variables, not for laziness, but because they don't know whether using and existing one will have any side effects anywhere else in the code base, so please don't use them or at least keep it at minimum.

CEO at: - Rafaga Systems - Para Facturas - Modern Components for the moment...