Float matrix passed as a parameter to a function gives garbage values

Question

I want to pass a float matrix to another function from the main function, the code being as follows:

#include <stdio.h>
 
// n must be passed before the 2D array
void print(int m, int n, float arr[][n])
{
    int i, j;
    for (i = 0; i < m; i++)
      for (j = 0; j < n; j++)
        printf("%d ", arr[i][j]);
}
 
int main()
{
    float arr[][3] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
    int m = 3, n = 3;
    print(m, n, arr);
}

This gives the output: 3 -1742458874 -1742458874 -1742458874 -1742458874 -1742458874 -1742458874 -1742458874 -1742458874

I tried this by replacing float with int for the type of the array and it works perfectly fine. I expected it would work the same way with float, outputting "1 2 3 4 5 6 7 8 9" but instead it outputs garbage values.

Answer 1

%d is the wrong format for floats. Using %f should solve the issue, and you should see the expected results. If you want to print only the "whole" part of the float, you can specify the precision too:

printf("%.0f ", arr[i][j]);