title: how to work with parameters in fixes, the fixes are pointers?
body: <p>I want to generate a 16x16 matrix of characters that contains the letter "o" in upper case, and then save it in a text file</p>
  
  <pre><code>#include&lt;stdio.h&gt;
  #include&lt;stdlib.h&gt;
  #include&lt;string.h&gt;
  #include&lt;conio.h&gt;
  
  char generate_matrix(){
      int colum=16,j;
      int rows=16,i;
      for (i=0;i&lt;rows;i++){
          for(j=0;j&lt;colum;j++){
              matrix[i][j]='O';
  
  
          }
      }
      return matrix;    
  }
  void save(char matrix[16][16]){
      FILE*archivo;
      int i,j;
      char address[]="C:\\Users\\Usuario\\Desktop\\mat.txt";
  
      archivo=fopen(addres,"w");
      if(archivo==NULL){
          printf("does not exist");
      }
      else{
          printf("exist");
      }
      for(i=0;i&lt;16;i++){
          for(j=0;j&lt;16;j++){
          fprintf(archivo,"%c\t",matrix[i][j]);   
          }
          fprintf(archivo,"\n");
      }
  
      fclose(archivo);
  
  }
  
  int main(void){
      generate_matrix();
      save(matrix);
  
      return 0;
  }
  </code></pre>
  
  <blockquote>
    <p>ERROR</p>
    
    <p>In function 'generate_matrix': error: 'matriz' undeclared (first use in
    this function)<br>
                 matrix[i][j]='O';<br>
                 ^~~~~~<br>
    note: each undeclared identifier is reported only once   for each function it appears in matrix.c: In function 'main':<br>
    error: 'matriz' undeclared (first use in this function)<br>
         save(matrix);<br>
                 ^~~~~~  </p>
  </blockquote>
  
  <p>please help me, I'm just starting in c
  I do not know if the error is because I have to pass the matrix by pointer?
  or how can I pass it as a parameter</p>