C++ - Passing 2D array to function [duplicate] - c++

Question

This question already has answers here:
Passing a 2D array to a C++ function
(17 answers)
Variable length arrays (VLA) in C and C++
(5 answers)
Closed 3 months ago.
I am trying to pass a 2D array to a function but I am failing to do so. There is no problem with passing 1D array. How can I do this?
#include <iostream>
using namespace std;
void DisplayBoard(int matrix[],int n) // Prints out the given array.
{
for (int j = 0; j < n; j++)
{
cout << matrix[j];
}
}
int main()
{
int n,m;
cin>>n;
//int matrix[n]={};
DisplayBoard(matrix,n);
return 0;
}

Answer 1

i think you want to input index number (n) from user and then input array object from user too
i complete your code like this :
#include <iostream>
using namespace std;
void DisplayBoard(int matrix[],int n) // Prints out the given array.
{
cout<<endl ;
for (int j = 0; j < n; j++)
{
cout << matrix[j]<<" ";
}
}
int main() {
int n,m;
cin>>n ;
int matrix[n];
for(int i=0;i<n;i++) {
cin>>matrix[i];
}
DisplayBoard(matrix,n);
return 0;
}
remember to declare array in main function too ,
that was one of your code error !
and this is incorrect to declare array :
int matrix[n]={} // incorrect !

Answer 2

Well. int matrix[n]={}; fills it with zeros and that's what I wanted to do. And my code with 1D array works fine but if I do it like so it does not.
#include <iostream>
using namespace std;
void DisplayMatrix(int matrix[][],int n,int m)
{
for(int i=0;i<n;i++)
{
for (int j = 0; j < m; j++)
{
cout << matrix[j];
}
}
}
int main()
{
int n,m;
cin>>n>>m;
int matrix[n][m]={};
DisplayMatrix(matrix,n,m);
return 0;
}