Passing two-dimensional array via pointer

Question

How do I pass the m matrix to foo()? if I am not allowed to change the code or the prototype of foo()?

void foo(float **pm)
{
    int i,j;
    for (i = 0; i          


        

Answer 1

• you dont need to do any changes in the main,but you function will work properly if you change the formal prototype of your function to (*pm)[4] or pm[][4] because **pm means pointer to pointer of integer while (*pm)[4] or pm[][4] means pointer to poiner of 4 integers .
  

  m here is also a pointer to pointer of 4 integers and not pointer to pointer of integers and hence not compatible.

  #include
  void foo(float (*pm)[4])
  {
      int i,j;
      for (i = 0; i < 4; i++)
          for (j = 0; j < 4; j++)
              printf("%f\n", pm[i][j]);
  
  }
  
  int main ()
  {
      float m[4][4];
      int i,j;
      for (i = 0; i < 4; i++)
          for (j = 0; j < 4; j++)
                  m[i][j] = i+j;
  
      foo(m);
   }