invalid use of member?

[Vasthor]

what's the problem?
E:\Tools\Programming\C++ Programming\CodeBlocks\Project\Knowledge_Based_Project\Exercise_Temporary_Compiler\Exercise_Temporary_3\main.cpp||In function 'int main()':|
E:\Tools\Programming\C++ Programming\CodeBlocks\Project\Knowledge_Based_Project\Exercise_Temporary_Compiler\Exercise_Temporary_3\main.cpp|36|error: invalid use of member (did you forget the '&' ?)|
||=== Build finished: 1 errors, 0 warnings ===|

#include <algorithm>
#include <iomanip>
#include <iostream>
#include <string>
#include <vector>

using namespace std;

int main()
{
    // informed user
    cout << "Please insert several amount of number: /n";

    // input
    int inputs;
    vector<int> numstore;

    while (cin >> inputs)
        numstore.push_back(inputs);


    // re-arrange element in vector.
    sort(numstore.begin(), numstore.end());

    // formed a loop that iterate through each ele in (numstore)
    const int quadro = 4;
    int quartiles = 1;
    vector<double> quaele;

    for (vector<int>::size_type counter = 0; (quartiles == quadro) || (counter < numstore.size()); ++counter)
        if (counter == (quartiles/quadro * numstore.size()))
        {
            quaele.push_back(numstore[counter]);
            if ((quartiles == 2) && (numstore.size / 2 == 0))
                quaele[quartiles-1] = (numstore[counter]+numstore[counter-1]) / 2;
            ++quartiles;
        }


    // outputting
    streamsize prec = cout.precision();
    cout << "Your final grade is: /n" << setprecision(3);

    for (vector<double>::size_type counter = 0; counter < quaele.size(); ++counter)
        cout << quaele[counter] << "/n";

    cout << setprecision(prec) << endl;

    // success indicator
    return 0;
}

[histrungalot]

numstore.size is a function, not a member. Add the () to get it to compile. And change /n to \n.

// Error
if ((quartiles == 2) && (numstore.size / 2 == 0))
// Fixed
if ((quartiles == 2) && (numstore.size() / 2 == 0))

[Vasthor]

great, thnx, btw, on line 31 why does even counter == 0, the conditional if execute?

*no attachment*

just try to compile the program and see the result...

[histrungalot]

Not completely sure what you are asking.
The if executes because if you entered data on line 19 the check

(quartiles == quadro) || (counter < numstore.size())

is true. First part is false but second part is true. So, (false || true) = true
Is that what you were asking?

[Vasthor]

no,

I'm talking about the conditional in if not the for loop

i mean on the first loop, counter == 0

so, how can counter == 1(quartiles) / 4(quadro) * 10(element number), this is what I input

0 1 2 3 4 5 6 7 8 9

but then, it output

0

this is so weird, I mean the it will take the number in first element, and then the if condition continue to be false and that's what all it get, so how can counter == 0 == 1/4 * 10?

[histrungalot]

Because of integer divide. 1/4 is 0.25 but 0.25 as an integer is 0.
Hence, count == 0 == quartiles/quadro * 10(element number) == 0 * 10*size.
Once you cast one of them to a float or a double you get the result of 0.25.
Check out this code to see what I mean.

#include <iostream>
int main(){
  int quadro(4),quartiles(1);
  std::cout << "quartiles/quadro        = " << quartiles/quadro << std::endl;
  std::cout << "float(quartiles)/quadro = " << float(quartiles)/quadro << std::endl;
  std::cout << "quartiles/float(quadro) = " << quartiles/float(quadro) << std::endl;
  std::cout << "float(quartiles/quadro) = " << float(quartiles/quadro) << std::endl;
  return 0;
}

quartiles/quadro        = 0
float(quartiles)/quadro = 0.25
quartiles/float(quadro) = 0.25
float(quartiles/quadro) = 0

Also, the value of quartiles/quadro * numstore.size() must be a integer to be able to checks it's value with counter, because counter is an integer.