Code errors

[polodude8888]

Create three arrays of 20 integers each. Fill in two arrays with data, leaving the third blank. From main, pass these three arrays into a function. Inside the function, add the value of each array element and store it in the third.

third_array[i] = second_array[i] + first_array[i]

Back in main, print out the value of every element in the third/sum array. Excellent output on this assignment might show something like:

Array 1 + Array 2 = Array 3

5 + 3 = 8

10 + 4 = 14

I can't figure out how to add the elements of the arrays and display it

  #include <iostream>
  #include <array>
  using namespace std;
  const size_t rows{10};
  const size_t columns{2);
  void printArray(const array<array<int, columns>, rows>&);

  int main()
{
 array<array,int, columns>, rows> arrayOne{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20};
array<array,int, columns>, rows> arrayTwo{21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40};
array<array<int, columns> rows> arraySum[20];

cout << "The values of array one are: " << endl;
printArray(arrayOne);

cout << "The values of array two are: " << endl;
printArray(arrayTwo);

arraySum[i] = arrayOne[i] + arrayTwo[i];

cout << " Sum of array one and two is: ";
printArray(arraySum);
}
}
 

[knowclue]

The answer is in your question

third_array[i] = second_array[i] + first_array[i]

The arrays are all accessed by index so this is how you will populate the values in your third array. You will need a loop to cover all of your index values.

As for passing the values into a function you will need to make sure that you pass the arrays by reference so that they will be updated in main. See the difference in this tutorial http://www.cplusplus.com/doc/tutorial/functions/

[polodude8888]

Thanks. I'm trying to understand it, but it seems to be going over my head. I'm assuming my loop would need to be something similar to

int count;

for(count =0; count < 20; count++) {
cout << arrayOne[count];

As for passing the arrays by reference I'm not quite sure I get it. I think I'm hung up and wanting to make sure my output for the arraySum is also in columns and rows.

[knowclue]

Essentially, you will want two loops, thie first to populate your third array with the second to print it out.

The first loop will use this

arraySum[i] = arrayOne[i] + arrayTwo[i];

The second for displaying the output will be similar to the one here

for(count =0; count < 20; count++) {
cout << arrayOne[count]; //<-- this will only print the values from array one
//try something like this
//cout << FirstArrayVal << plus << secondArrayVal << eqaul << sumArrayVal << newline MM

Pass by reference essentially means that you are not passing a copy of the object, but the object itself. A brief example illustrating this point:

#include <iostream>
void passByVal(int x, int y)
{
    x=5;
    y = 10;
   std::cout << "passByVal: x = " << x << " y = " << y << "\n";
}

void passByRef(int& x, int& y)
{
   x = 5;
  y = 10;
  std::cout << "passByRef: x = " << x << " y = " << y << "\n";
}

int main()
{
    int x = 0;
    int y = 0;

   //show values of x and y before operations
   std::cout << "Main: x = " << x << " y = " << y << "\n";

   //notice the value of main after this
   passByVal(x,y);
   std::cout << "Main: x = " << x << " y = " << y << "\n";

   //notice the value after this
   passByRef(x,y);
   std::cout << "Main: x = " << x << " y = " << y << "\n";
}

Here is the output f the above code.
Main: x = 0 y = 0
passByVal: x = 5 y = 10
Main: x = 0 y = 0
passByRef: x = 5 y = 10
Main: x = 5 y = 10

[polodude8888]

Thank you so much. That cleared it up for me.