Quick Array Problem

I have the following code:

Code:

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#include <stdio.h>
#include <stdlib.h>

int max_rows;
int max_columns;
void print(char[][]);

int main(int argc, char *argv[]){
       
        max_rows = 3;
        max_columns = 3;
        char grid[max_rows][max_columns];
       
        for(int i = 0; i < max_rows; i++){
                for(int j = 0; j < max_columns; j++){
                        grid[i][j] = 'X';
                }
        }
       
        print(grid);
       
}

void print(char grid[max_rows][max_columns]){
       
       
        for(int i = 0; i < max_rows; i++){
                for(int j = 0; j < max_columns; j++){
                        printf("%c ", grid[i][j]);
                }
                printf("\n");
        }
       
}

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I get the following errors:

error: array type has incomplete element type (line: void print(char[][]);)
In function ‘main’:
error: type of formal parameter 1 is incomplete (line: print(grid);)

Any ideas???

Compile in C99 mode, otherwise you can't do what you're trying to do. Also, multi-dimension arrays are converted to a pointer to their type. So an array of array of ints becomes a pointer to an array of ints. And, it doesn't like that you're trying to not tell it how big the array is in the function declaration.


Quzah.

Could you possibly post an example of how to fix this?? I have to turn this in by midnight tonight and need to get it done. The reason I've set it up like this is because max_rows and max_columns will be specified by command line arguments.

Search the forums. Questions about creating dynamic arrays or dynamic multi-dimension arrays are pretty common.


Quzah.

This version runs well on old compilers:

Code:

---


#include <stdio.h>
#include <stdlib.h>

int max_rows;
int max_columns;
//we can pass this way without knowing the values of max rows and columns
//we could change it, if we knew the sizes at this point
void print(char**);

int main(int argc, char *argv[]){
       
        char **grid;
  int i, j;
        max_rows = 3;
        max_columns = 3;


  *grid = malloc(max_rows * sizeof(char*));

  for(i = 0; i < max_rows; i++)
      grid = malloc(max_columns * sizeof(char));  //not a pointer size
         
        for(i = 0; i < max_rows; i++){
                for(j = 0; j < max_columns; j++){
                        grid[i][j] = 'X';
                }
        }
       
        print(grid);
  //free each row
        for(i = 0; i < max_rows; i++)
      free(grid[i]);
  //then free the whole array
  free(grid);

  printf("\n\n\t\t\t      press enter when ready ");
  i = getchar();
  return 0;
}

void print(char **grid) {
  int i, j;       
       
        for(i = 0; i < max_rows; i++){
                for(j = 0; j < max_columns; j++){
                        printf("%c ", grid[i][j]);
                }
                printf("\n");
        }
       
}

---

Better you can check this program.It will work fine.

Code:

---

#include <stdio.h>
#include <stdlib.h>

int max_rows;
int max_columns;
void print(char grid[]){
int i,j;

        for( i = 0; i < max_rows; i++){
                for( j = 0; j < max_columns; j++){
                        printf("%c ", grid[i]);
                }
                printf("\n");
        }

}


int main(int argc, char *argv[]){

        max_rows = 3;
        max_columns = 3;
        int i,j;
        char grid[max_rows][max_columns];

        for( i = 0; i < max_rows; i++){
                for( j = 0; j < max_columns; j++){
                        grid[i][j] = 'X';
                }
        }

        print(grid[0]);

}

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good luck..

Quote:

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Originally Posted by karthigayan

Better you can check this program.It will work fine.
good luck..

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As was already stated it will not work in the C90 mode