Thread: function and array assistance please

The function char findMonth(int) is supposed to return the month
that corresponds to the number entered by the user.

The int lowestRainfall () function is supposed to return the month with the lowest rainfall.

These are the errors I get when i compile

rainfalls.cpp: In function `char findMonth(int)':
rainfalls.cpp:63: error: declaration of 'char months[12][10]' shadows a parameter
rainfalls.cpp: In function `int lowestRainfall(int (*)[2])':
rainfalls.cpp:78: error: `sum' undeclared (first use this function)
rainfalls.cpp:78: error: (Each undeclared identifier is reported only once for each function it appears in.)
rainfalls.cpp:79: error: `months' undeclared (first use this function)
rainfalls.cpp:79: error: `monthNum' undeclared (first use this function)
rainfalls.cpp:83: error: expected `}' at end of input

Code:

#include <iostream>

using namespace std;

void getData(int rainfall[12][2]);
int averageHigh(int rainfall[12][2]);
int averageLow(int rainfall[12][2]);
char findMonth(int months);
int main()
{
    int rainfall[12][2];
    char months[12][10]={"January","February","March","April","May","June","July","August","September","October","November","December"};
    int monthNum;

    getData(rainfall);
    averageHigh(rainfall);
    averageLow(rainfall);
    findMonth(monthNum);

    return 0;

}
void getData(int rainfall[12][2])
{
    for (int i = 0; i < 12; i++)
    {
                cout << "Please enter the highest and lowest amount of rainfall for the month." << endl;
                cin >> rainfall[i][0] >> rainfall[i][1];
    }
}

int averageHigh(int rainfall[12][2])
{
                double sum=0;
                double average=0;
                 for(int a=0;a<12;a++)

        {
                sum+=rainfall[a][0];
        }
                average=sum/12.0;
                cout<<"Average high is- "<<average<<endl;



}
int averageLow(int rainfall[12][2])
{
                double sum=0;
                double average=0;
                for(int a=0;a<12;a++)

        {
                sum+=rainfall[a][1];
        }
                average=sum/12.0;
                cout<<"Average low is- "<<average<<endl;
}
char findMonth(int months)
{
                int monthNum;

                char months[12][10]={"January","February","March","April","May","June","July","August","September","October","November","December"};

                cout<<"Please enter the number of the month"<<endl;
                cin>>monthNum;

                cout<<months[monthNum][10];
}

int lowestRainfall(int rainfall[12][2])
{
           int low;

                 for(int a=0;a<12;a++)

        {
                sum+=rainfall[a][1];
                months[monthNum][10];


        }
                cout<<"The month with the lowest rainfall is "<<low<<endl;

well i see you have not declared function lowest rainfall

There are a number of problems with this code that can very easily be alleviated using std::string and std::vector. I'm curious as to why you chose a vanilla C/C++ approach instead of using standard containers that can handle all of what you're trying to do and make it very, very easy.

As for the very first error, it's talking about this:

Code:

void getData(int rainfall[12][2])

I don't know the exact reasoning behind the compiler error but basically you can't declare an array like that as a function parameter. You'd be better off typedefing it and passing a pointer to it although I can't say that's even correct because I don't use C.

You'd be in much better shape defining a vector<vector<int> >. You can access it the sameway (using subscribt operators, [x][y]) but storage and handling of it is a lot easier.

You have functions which are returning char's but it looks like you're expecting whole strings. This won't work. At best you'll get the first character from a month string.

If you change your function parameter lists and make use of STL's containers you'll find that most, if not all, of those errors will disappear. Your code will be more maintainable, easier to read and easier to work with.

you can pass array like that as a parameter? this from a previous post

Code:

#include <stdio.h>
#include <stdlib.h>

void AlterArray(int myarray[5])
{
    myarray[2] = 60;
}


int main(int argc, char *argv[])
{
    int myarray[5] = { 10,20,30,40,50 };

    printf("my array 3rd element: before call > %d \n",myarray[2]);

    AlterArray(myarray);

    printf("my array 3rd element: After call > %d \n",myarray[2]);

    system("PAUSE");
    return 0;
}