Doing homework for a class I'm not enrolled in

[sciman777]

Hello! I'm trying to learn C++ by having my friend in class send me his homework and me just doing it on my own, I've been able to keep up until now, I have no idea how to do this:

https://imgur.com/a/qykyQ

I know what a structure/class is, I know arrays, but I just don't understand what the assignment wants me to do, it's written in such a complicated way.

I'm not asking for the solution, just some guidance on where to even begin, or some hints on how to solve it.

Thank you!

[tpb]

Can you do the first 4 things? Show your code. What about the 5th one (the 2D array and initializing it)?

[sciman777]

Heres the code I wrote so far

#include <iostream>
#include <string>

enum Section
{
    ORCHESTRA,
    FRONT,
    MIDDLE,
    BACK,
    double const cdaPrice[3] = {150,100,75,50}

};

struct Date
{
public:
    int iDay, iMonth, iYear;

};

struct Seat
{
public:
    char cRow;
    int iColumn;
    Section SeatPrice;
    bool bAssigned;
    std::string sName;
    Date Day;
};


int main()
{


    return 0;
}

I did something wrong with the const double, the compiler is getting confused at that part.

[Ganado]

You need a semi-colon at the end of line 10. But you also have only allocated an array of size 3, yet you are trying to give it 4 elements. Replace the 3 with a 4.

You can created a 2-dimensional array like so:

Seat seats[26][50];

To learn about functions, I suggest the tutorial on the site
http://www.cplusplus.com/doc/tutorial/functions/

However, arrays can be annoying to pass, it's a bit unintuitive, so here's an example of passing a 2D array:

void func(int arr[][50])
{
    arr[5][10] = 42;
}

int main()
{
  int arr[26][50];
  
  func(arr);
}

You can also add named constants to keep track of what those numbers actually mean:

const int NumColumns = 50;
const int NumRows = 26;

void func(int arr[][NumColumns])
{
    
}

int main()
{
  int arr[NumRows][NumColumns];
  
  func(arr);
}

[sciman777]

Is that so? I thought arrays were counted from 0, so 4 elements means it should be 3?

Adding the semicolon did not fix the error. I thought they all had to end with a comma?

I know how to use functions and declare arrays, I just don't understand what the assignment wants me to do,


and 2) how I can pass an array of the Seat Structure to a function? It's obviously not the same way as passing a regular array of like ints or something.

all help appreciated, thanks

[Ganado]

See my edit for passing a 2d array.

Yes, indices start at 0. But the declared size itself is still its size.
An array of size 5 has indices 0 to 4. Hope that makes sense.

int arr[5] = {2, 4, 5, 8, 9};
// arr[0] is 2
// arr[4] is 9 

Adding the semicolon did not fix the error.

So, change
double const cdaPrice[3] = {150,100,75,50}
to
double const cdaPrice[4] = {150,100,75,50};

EDIT:
I didn't notice you had your array declaration inside an enum. Move the declaration of your cdaPrice array to outside of the enum declaration.

[sciman777]

EDIT: Nevermind, I'm doing good at the moment, thanks for all your help! I will post if I do something wrong again.

[E0p9LyTq]

'A' is not 0 + 17, it is ASCII code 65.

#include <iostream>

int main()
{
   for (char loop = 'A'; loop <= 'Z'; loop++)
   {
      std::cout << loop << ' ';
   }
   std::cout << "\n\n";

   for (char loop = 'A'; loop <= 'Z'; loop++)
   {
      int num = loop - 65;
      std::cout << num << ' ';
   }
   std::cout << '\n';
}

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

[zaphraud]

Try it simplified and find out

$ cat ascii.cpp
#include <iostream>
using std::cout;

int main(){

        int iY=0, val=0;
        char test;
        test = (char)iY+17;
        val = test;
        cout << test << "\n" << val;
        }

It just produces "17" as output, which is a ctrl-q.

You've asked it to use a char datatype, but that doesn't make a VALUE of zero into a value of "0". It makes an int with a value of zero into a NUL.

Add 65 instead.

[E0p9LyTq]

You can have your Section enum store the prices directly as part of the enumeration.

 enum Section
   {
      ORCHESTRA = 150, FRONT = 100, MIDDLE = 50, BACK = 50
   };

   std::cout << FRONT << '\n';

100