[nfbcs] [program-l] Re: Re: Help with Another Assignment

[Mike Gorse]

Hi Lanie,

You're not getting a rounding error, although it might look like one.

When i == 3, grades[3] is read. You increment notCompleted but not i.
In the next iteration, you read grades[i] again, and i is still 3, so, 
instead of reading the next grade, you read grades[3] again, and so on. 
You didn't fix your loop correctly. You're using i to refer to the 
position in the array, not the number of completed grades, so i should be 
incremented whether the grade is -1 or not.


On Sat, 4 Nov 2017, Lanie Molinar via nfbcs wrote:

> I’m resending this since it didn’t go to both lists last time. I fixed the issue with my loop and got it working, but now I seem to be having a rounding error in test 2 of the testbed. I tried using floats with cout.setf(ios::fixed), and cout.precision(2), but they only fixed part of the problem I was having. I’m not sure what else I can do to fix this.
>
> Sent from Mail for Windows 10
>
> From: Dzhovani Chemishanov
> Sent: Friday, November 3, 2017 2:46 PM
> To: program-l at freelists.org
> Cc: Lanie Molinar via nfbcs
> Subject: [program-l] Re: [nfbcs] Re: Help with Another Assignment
>
> Mike is quite right. A good thing is to open random online tutorial
> and read carefully what any of them have to say about loops because
> the theoretical stuff really matters.
>
> On 11/3/17, Mike Gorse <mike at straddlethebox.org> wrote:
>> I'm intentionally being a little vague and trying to help you find the
>> problem with your code, rather than feeding a solution to you, since
>> debugging is an important part of programming and, thus, part of what you
>> need to be learning, and that might mean inspecting your code, or
>> temporarily inserting statements to print things, or using a debugger, or
>> some combination. Anyhow, you have
>> while (i < num)
>> so your loop will execute until i == num
>>
>> If there is a case where i does not change and neither does num and
>> nothing happens that will cause them to change in any future iteration,
>> then the loop will continue to execute forever, and you'll need to
>> terminate your program.
>>
>> On Fri, 3 Nov 2017, Lanie Molinar wrote:
>>
>>>
>>> I have no idea how to fix this one. Any suggestions?
>>>
>>>
>>>
>>> Sent from Mail for Windows 10
>>>
>>>
>>>
>>> From: Mike Gorse
>>> Sent: Friday, November 3, 2017 10:48 AM
>>> To: Lanie Molinar via nfbcs
>>> Cc: Lanie Molinar; program-l at freelists.org
>>> Subject: Re: [nfbcs] [program-l] Re: Help with Another Assignment
>>>
>>>
>>>
>>> I wouldn't say that you're getting a blank line, so much as that your
>>>
>>> program is locking up. Looking at your while loop in averageGrades(), it
>>>
>>> isn't going to terminate in some cases.
>>>
>>>
>>>
>>> On Fri, 3 Nov 2017, Lanie Molinar via nfbcs wrote:
>>>
>>>
>>>
>>>> I fixed it and got it to stop giving me errors, but I’m now having
>>>> another issue. For the condition that’s supposed to cout dashes, I get
>>>> only a blank line after I enter -1 for all 10 grades.
>>>
>>>>
>>>
>>>> Sent from Mail for Windows 10
>>>
>>>>
>>>
>>>> From: Dzhovani Chemishanov
>>>
>>>> Sent: Friday, November 3, 2017 9:22 AM
>>>
>>>> To: Lanie Molinar
>>>
>>>> Cc: program-l at freelists.org; Lanie Molinar via nfbcs
>>>
>>>> Subject: Re: [program-l] Re: [nfbcs] Help with Another Assignment
>>>
>>>>
>>>
>>>> Hi,
>>>
>>>>   As I said, my c++ is rusty but still I'd be quite surprised to find
>>>
>>>> working code of the type:
>>>
>>>> cout << some_text << a_void_function();
>>>
>>>> It is okay to have a cout statement in a void function, but it is not
>>>
>>>> okay to have a void function in a cout statement.
>>>
>>>> Any other type of function that returns printable result could be
>>>
>>>> called from a cout, but the fundamental property of void functions is
>>>
>>>> that they do not return value to be sent to the c out stream.
>>>
>>>>   Can you check your previous project and compare the approach there
>>>
>>>> with the current one?
>>>
>>>>
>>>
>>>> On 11/3/17, Lanie Molinar <laniemolinar91 at gmail.com> wrote:
>>>
>>>>> Hi. I’ve used cout statements this way in a void function before,
>>>>> though, so
>>>
>>>>> I don’t understand why it doesn’t work. In a project I did just a
>>>>> couple
>>>
>>>>> weeks ago, I created a display function that was void but had multiple
>>>>> cout
>>>
>>>>> statements in it. This seems like the same kind of thing.
>>>
>>>>>
>>>
>>>>> Sent from Mail for Windows 10
>>>
>>>>>
>>>
>>>>> From: Dzhovani Chemishanov
>>>
>>>>> Sent: Friday, November 3, 2017 8:26 AM
>>>
>>>>> To: program-l at freelists.org
>>>
>>>>> Cc: Lanie Molinar via nfbcs; laniemolinar91 at gmail.com
>>>
>>>>> Subject: Re: [program-l] Re: [nfbcs] Help with Another Assignment
>>>
>>>>>
>>>
>>>>> this line
>>>
>>>>> cout << "Average Grade: " << averageGrades(grades, NUMGRADES) <<
>>>>> "%\n";
>>>
>>>>> the function that you are calling is void and you can't print result
>>>
>>>>> from it because it doesn't return anything.
>>>
>>>>> move all cout statements in it and avoid all the mess.
>>>
>>>>> Also, my cpp is rusty, so I hope that the way you are trying to fill
>>>
>>>>> in the array is valid.
>>>
>>>>> HTH,
>>>
>>>>> Dzhovani
>>>
>>>>>
>>>
>>>>> On 11/3/17, Mike Gorse <mike at straddlethebox.org> wrote:
>>>
>>>>>> Hi Lanie,
>>>
>>>>>>
>>>
>>>>>> If I try to compile your code, then I get this error:
>>>
>>>>>>
>>>
>>>>>> a31.cpp:71:30: error: no match for ‘operator<<’ (operand types are
>>>
>>>>>> ‘std::basic_ostream<char>’ and ‘void’)
>>>
>>>>>>       cout << "Average Grade: " << averageGrades(grades, NUMGRADES) <<
>>>
>>>>>> "%\n";
>>>
>>>>>>
>>>
>>>>>> The "void" is the key here--the compiler thinks that you are trying
>>>>>> to
>>>
>>>>>> pass something with a void type to the stream. From that, I'd guess
>>>>>> that
>>>
>>>>>> averageGrades() isn't returning a value. When I look at the function
>>>
>>>>>> prototype, it is, in fact, returning void, rather than returning a
>>>>>> value
>>>
>>>>>> that can be printed by the caller.
>>>
>>>>>>
>>>
>>>>>> Hth,
>>>
>>>>>> -Mike
>>>
>>>>>> ---311908982-671148510-1509712654=:14384--
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