User defined row, column output in C++ - c++

Question

I have a 2 part question. I am showing a user defined array. User input is # of rows, columns, and at what interval in the array to put a symbol.
I cannot get an output of the default symbol ****.
Where do I need to insert the interval input to adjust the array accordingly? Inside the function itself or define another function to do this?
I am looking for this result. Input = 1 (row), 4 (columns), 2 (interval). Output would be **?*.
Here is what I have so far.
#include <iostream>
using namespace std;
int rows = 0, columns = 0, interval = 0;
char symbol;
void Display(int rows = 0, int columns = 0, int interval = 0, char symbol = ('*'));
int main()
{
cout << "Enter number of rows: ";
cin >> rows;
cout << "Enter the number of columns: ";
cin >> columns;
cout << "Enter the number of the question mark interval: ";
cin >> interval;
cout << "\n";
cout << "How many rows do you want? " << rows << "\n";
cout << "How many columns do you want? " << columns << "\n";
cout << "How far between question marks? " << interval << "\n";
Display(rows, columns, interval, symbol);
return 0;
}
void Display(int rows, int columns, int intervals, char symbol)
{
for (int y = 1; y <= rows; y++)
{
for (int x = 1; x <= columns; x++) {
cout << symbol;
}
cout << endl;
}
system("pause");
}

Answer 1

The problem is you never assigned * to symbol.
Change
char symbol;
to
char symbol = '*';
Did you know about the disadvantages of global variables. The sooner you learn about the cons the better. Here is a starting point.
Modify the Display function as below:
void Display(int rows, int columns, int intervals, char symbol)
{
for (int y = 1; y <= rows; y++)
{
for (int x = 1; x <= columns; x++) {
if ((x % (interval + 1)) == 0) //<--since you want after every intervals, just do a mod operation
cout << "?";
else
cout << symbol;
}
cout << endl;
}
system("pause");
}
Here is the working example.