Thread: obscure code and clear code

I have a real problem with programmers that write obscure code. Just to illustrate what I mean, here are two programs that do exactly the same thing. They calculate the powers of numbers one through ten from the first to the fourth power, and then print the results on the screen.

Tell me which coding is easier to understand: the first one or the second one.

First one:

Code:

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

int pwr(int a, int b);

int main(void)
{
  /* Declare a pointer to an array that has 10
     ints in each row. */
  int (*p)[10]; 

  register int i, j;

  /* allocate memory to hold a 4 x 10 array */
  p = malloc(40*sizeof(int));

  if(!p) {
    printf("Memory request failed.\n");
    exit(1);
  }

  for(j=1; j<11; j++)
    for(i=1; i<5; i++) p[i-1][j-1] = pwr(j, i);

  for(j=1; j<11; j++) {
    for(i=1; i<5; i++) printf("%10d ", p[i-1][j-1]);
    printf("\n");
  }
  system("PAUSE");
  return 0;
}

/* Raise an integer to the specified power. */
pwr(int a, int b)
{
  register int  t=1;

  for(; b; b--) t = t*a;
  return t;
}

Second one:

Code:

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

/* function declaration */
int pwr(int power, int base);

int main(void)
{
  /* declare a pointer to an array that has 10
     ints in each row. */

  int (*p)[10]; 

  /* declare row and column variables, respectively */
  int i, j;

  /* allocate memory to hold a 4 x 10 array */
  /*arrays are arranged as array[row][column]*/

  p = malloc(40*sizeof(int));

  if(!p)
  {
    printf("Memory request failed.\n");
    exit(1);
  }

  /* In the following for loop, the power is represented by i,
     the row of the array; the base is represented by j,
     the column of the array.*/

  for(i=1; i<5; i++) /* outer loop --> row */
  {
    for(j=1; j<11; j++) /* inner loop --> column */
    {
      p[i-1][j-1] = pwr(i, j);
    } /* end of inner loop */
  } /* end of outer loop */

  for(i=1; i<5; i++) /* outer loop --> row */
  {
    for(j=1; j<11; j++) /* inner loop --> column */
    {
     printf("%6d ", p[i-1][j-1]);
    } /* end of inner loop */
    printf("\n");
  } /* end of outer loop */

  printf("\n\n");

  system("PAUSE");
  return 0;
}

/* function definition */

pwr(int power, int base)
{
  int  t=1;

  for(; power != 0; power--) t = t*base;
  return t;
}

Thanks for the suggestions, Salem. I took you up on them. The very first code listing of this thread came straight out of a book on C! The second one was a rough draft trying to improve the readability of the code so future programmers wouldn't have to struggle with it.

Here's the new code listing:

Code:

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

/* function declaration */
int power(int power, int base);

int main(void)
{
  int (*p)[10];

  int row, col;

  /* allocate memory to hold a 4 x 10 array */

  p = malloc(4*sizeof *p);

  if(!p)
  {
    printf("Memory request failed.\n");
    exit(1);
  }


  for(row=1; row<5; row++)
  {
    for(col=1; col<11; col++)
    {
      p[row-1][col-1] = power(row, col);
    }
  }


  for(row=1; row<5; row++)
  {
    for(col=1; col<11; col++)
    {
     printf("%6d ", p[row-1][col-1]);
    }
    printf("\n");
  }

  printf("\n\n");

  system("PAUSE");
  return 0;
}

/* function definition */

power(int power, int base)
{
  int  t=1;

  for(; power != 0; power--) t = t*base;
  return t;
}

Wow, prelude! I am very impressed! Your C coding acumen leaves me dazzled and awed.

It never occurred to me that the program coding didn't need an array assignment or anything like that. The book I got the first code listing from was just trying to illustrate the use of pointers. So I took the pointers for granted without realizing that it was merely used for the sake of illustration.

Kudos to ya, prelude!

I suggest looking at as many different sources of code as you can, like here on the boards. After I branched out from my first book I was able to see things I liked and didnt like about it, as well as good and bad things. Dont always consider that a book will have good code, I've seen many examples of either completely incomprehensible or broken code in books from people such as Deitl and Deitl (main book used to teach corporate employees) and Bjarne Stroutrup ( the man who created C++).