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[Starver]

he's not just doing a while loop, he's doing a do...while loop.

Sorry, sloppy terminology...  "The loop with the 'while' termination" is what I was meaning.  Elsewhere I gave it a fuller description, but obviously it could cause confusion the way I referenced it that shorter way.

And, to that end, I wasn't going to say anything but...

[...]but even if you want it as a do while loop

the cin should be inside of it, or else it would only work the first time. then when it goes back to it to try it again the value that was used as nselector the first time would be kept every other time it ran.
so you should either include the cin inside the loop, and/or reset the nselector value for each rerun of the program.

...but the nSelection is within that loop, isn't it?  It does get refreshed, doesn't it?  I may be getting confused as to language dialect, but it certainly seems to do.

and I feel stupid for not even noticing he used return instead of cout.

Well, neither did I, I suppose, or rather I was reading it as an internal function that was misbehaving instead of a stand-alone program for which the return value is available to the shell, depending on the system it's on, but probably not what I'd do.

[Valid_Dark]

Spoiler (click to show/hide)

...blahblahblah....
int nSelection;

tryAgain:
    do
    {
        cout << "Please make a selection:" << endl;
        cout << "1:Addition" << endl;
        cout << "2:Subtraction" << endl;
        cout << "3:Multiplication" << endl;
        cout << "4:Division" << endl;
        cin >> nSelection;
    }while (nSelection != 1 && nSelection != 2 && nSelection != 3 && nSelection != 4);


    switch(nSelection)
    {
        case'1':
            return nX + nY;
        break;//prevents it from this and all below(called fallthrough)
        case'2':
            return nX - nY;
        break;//Prevents fallthrough
        case'3':
            return nX * nY;
        break;//Prevents fallthrough
        case'4':
            return nX / nY;
        break;//prevents fallthrough
        default:
            cout << "Error" << endl;
            goto tryAgain;
    }

he's not just doing a while loop, he's doing a do...while loop.

Sorry, sloppy terminology...  "The loop with the 'while' termination" is what I was meaning.  Elsewhere I gave it a fuller description, but obviously it could cause confusion the way I referenced it that shorter way.

And, to that end, I wasn't going to say anything but...

[...]but even if you want it as a do while loop

the cin should be inside of it, or else it would only work the first time. then when it goes back to it to try it again the value that was used as nselector the first time would be kept every other time it ran.
so you should either include the cin inside the loop, and/or reset the nselector value for each rerun of the program.

...but the nSelection is within that loop, isn't it?  It does get refreshed, doesn't it?  I may be getting confused as to language dialect, but it certainly seems to do.

first of all, I was too lazy to type out nSelection and figured you'd know what I meant by nselect, lol

and it is withen the loop, but the cin nSelection isn't in the loop in a way that it would EVER be called more than once,

look, it only does
do
    {
        cout << "Please make a selection:" << endl;
        cout << "1:Addition" << endl;
        cout << "2:Subtraction" << endl;
        cout << "3:Multiplication" << endl;
        cout << "4:Division" << endl;
        cin >> nSelection;
    }
while
while (nSelection != 1 && nSelection != 2 && nSelection != 3 && nSelection != 4); equals one
so as soon as you enter a number / assign a number to nSelection that while expression equals 0,
so you'll never be able to cin >> nSelection again.


right? or am I missing something?

[Rgamer]

You're right,Valid_Dark. And thanks for the advice, by the way. It fixed ze program very gud. And removing excess gotos is good,so to the guy who advised that (Forgot your name already), thanks a lot.

[Valid_Dark]

I really enjoy fixing peoples code, it refreshes my memory on certain aspects I don't always use.
I haven't been coding for very long, but it's always good to share what I know,
my first week learning c++ i was correcting people on some stupid c++ forum,
(someone said +=  -= *= etc. dont work in c++, and I was like whaaaaat??" etc.)
and when I'm learning something new and can't figure out why it's not working I ask for help too, it's much faster to ask someone who's been through it rather than sit and ponder about it for a day or two pulling your hair out trying everything until it works.
although last time I asked for help someone said they'd help me but never did.   
I've only been learning c++ for a few months, all self taught. (from a very good book, i tried learning from online tuts and none were nearly as good as this book I got, and couldn't find any good ebooks, or when I did I found out I much prefer to learn from a physical book)
everything is a learning experience.  I really need to work on my game some more but keep procrastinating.
I have bursts of inspiration that come and go.

[Normandy]

the ascii of 1-9 is 1-9.

The ascii value of 1-9 is actually 49-57.

[Valid_Dark]

you're right, I don't remember where I heard that.
anyways I NEVER go from memory when working with ascii, I always look up a chart.

[Starver]

first of all, I was too lazy to type out nSelection

You saved a massive one character with "nSelector" instead of "nSelection", you know.   And we've wasted more on the after-talk.  Didn't look like a typo, and I really wanted to make sure we were talking about the same thing.

and it is withen the loop, but the cin nSelection isn't in the loop in a way that it would EVER be called more than once,

"Please enter 1, 2, 3 or 4:"
<enters '5'>
"Please enter 1, 2, 3 or 4:"
<enters '9'>
"Please enter 1, 2, 3 or 4:"
<enters '2'>
"Finally, right, now I'll do the calculation you desire..."

as soon as you enter a number / assign a number to nSelection that while expression equals 0,
so you'll never be able to cin >> nSelection again.

Which is how I saw the program as being 'designed' to work.  After asking for the two initial numbers to work with ask (by way of a multichoice) for a single operation to apply to them.  Keep asking until it's a valid choice, then do the appropriate operation and exit.

You were thinking it should repeat the choice?  I'd also surround the two initial 'data' numbers as well as the 'operation' choice number (or other key).

In which case, make sure there's a "I don't want to do anything more with this" choice on the menu, otherwise you can only terminate the program by a Ctrl-C/equivalent.  Perhaps double loop it with a "finished with these numbers, break out of the 'operator choice loop' and hit the 'data numbers input loop' repeater, as well as an option that breaks out of this second one as well.

Code: (Pseudocode) [Select]

RedoAllLoop:
  Set NewNums as True
  Ask for two numbers to calculate with
  RedoOperationLoop:
    Set NewOp as True
    Ask for operation to apply
    Case Operator 1 -> do Operation1 on Numbers; break out of Case
    Case Operator 2 -> do Operation2 on Numbers; break out of Case
    ...Operator 3, 4, any more, ditto...
    Case NewNumbers -> Set NewOp=False; break
    Case Finished -> Set NewNums=False; break
    Case anythingelse -> Tell the user they did it wrong; (optional) break
  repeat RedoOperationLoop while(NewOp && NewNums)
repeat RedoAllLoop while(NewNums)
Goodbye...

As to the char==value, some languages are 'loose' with values being equatable to value-evaluated strings.  Perl, for example and if I've not made a thinko as I type this, has "if ($x == 0)" and "if ($x == '0')" and "if ($x eq '0')" being the same (and also "if (!$x)", but that would also catch it being undefined, which you might want, but maybe don't)...

Powerful, but prone to error.

If you want to work at a very low level, bitwise (by whatever operators the language you use provides), you can convert ASCII numbers to decimals by ANDing the char's ordinal value with 15, but it isn't foolproof (all characters give values, and across 0..15).  Prevalidating by aiming to see zero come out of the ordinal value ANDed with 192, first, helps, and then non-zero from the ordinal ANDed with 48 but you've still got more out-of-range numbers (for decimal), and it rapidly gets complicated if you've not got a neat 0..2ⁿ-1 range, and so instead of 1..4 I'd go for 0..3, ORing out the last two bits once I had checked it matches "001100??" (two checking operations needed, either in series or chained together).  Matching 1..4 would mean "00110???" as the template, but then take measures to exclude the four other values that could include.  And, besides, that's unnecessarily complicated for anything beyond low-level.  And I may have typoed/thinkoed along the way, and I'd need to properly go through it to be absolutely sure I've covered all the truth-table possibilities...

edited for a couple of thinkos/typos, more probably remain...

[MaximumZero]

Code: [Select]

Case anythingelse -> Tell the user they did it wrong; (optional) break

cout<<"You did it wrong, fucktard! Do it again, and do it right this time!";

[Deadmeat1471]

Code: [Select]

Case anythingelse -> Tell the user they did it wrong; (optional) break

cout<<"You did it wrong, fucktard! Do it again, and do it right this time!";

XD

[Valid_Dark]

Which is how I saw the program as being 'designed' to work.  After asking for the two initial numbers to work with ask (by way of a multichoice) for a single operation to apply to them.  Keep asking until it's a valid choice, then do the appropriate operation and exit.

>.<
i'm stupid, I just saw that he had the goto and assumed what he wanted it to do.
you're probably right and it was probably only designed to run once.
>.<

[Kofthefens]

Just teaching myself Java, how do you listen for keyboard events? Specifically, the left and right arrow keys.
EDIT: And also, how do you change the text of a JLabel, once it has been drawn?

[Virex]

Just teaching myself Java, how do you listen for keyboard events? Specifically, the left and right arrow keys.

Extend your Jframe or JPanel with a Keylistener interface. The codes for the left and right keys are VK_LEFT and VK_RIGHT

EDIT: And also, how do you change the text of a JLabel, once it has been drawn?

Use the setText method of the JLabel. It should redraw automatically. If not, call redraw on it or one of it's parent containers.

[Kofthefens]

EDIT: Never mind, problem solved.

Editing an Edit: How do you make a random number between a negative and a positive, eg -100 and 100?

[qwertyuiopas]

Simple math. If there is already a function to generate a random number from a range, use it. If there is one that generates from 0 to <max>, give it <higher - lower> as max, and then add <lower> afterwards. If you can only get one between 0.0 and 1.0, multiply by <higher - lower> and then add <lower>.

[Kofthefens]

Thanks.