repetition with the "for" structure

thanks for your help the last time, guys. I now have a question re: the "for" structure.

This code for printing a diamond has more than one "for" statement and I don't understand how to interpret it. I have seen the output, but I can't follow it from the code.

Could someone please explain?

here goes the code...

Code:

int main ()
{
   int  line, space, asterisk;

   for (line = 1; line <= 9; line += 2)	          /* 	Top half	*/
   {
   for (space = (9 - line) /2; space > 0; space--)
         printf (" ");

   for (asterisk = 1;  asterisk <= line;  asterisk++)
         printf("*");

   printf ("\n");
    }

   for (line = 7;  line >= 0;  line -= 2)	          /*Bottom half	*/
   {
   for (space = (9 - line) /2; space > 0; space--)
         printf (" ");

   for (asterisk = 1;  asterisk <= line;  asterisk++)
         printf("*");

   printf ("\n");
    }

   return (0);
}

Code Tags added by Kermi3

I am posting this because you did not use code tags on this thread. In the furture please use Code Tags. They make your code MUCH easier to read and people will be much more likely to help you if you do. And they'll be happy about helping you


For example:

Without code tags:

for(int i=0;i<5;i++)
{
cout << "No code tags are bad";
}

With Code Tags:

Code:

for(int i=0;i<5;i++)
{
     cout << "This code is easy to read";
}

This is of course a basic example...more complicated code is even easier to read with code tags than without.

I've added code tags for you this time. They can be added by putting [code] at the beginning of your code and [/code] at the end. More information on code tags may be found at the link in my signature. I also suggest you take a look at the board guildlines if you have not done so already. Any further questions or ways I can help please feel free to PM me.

Good Luck,
Kermi3

i'm totally green. I didn't intend to flout your rules.

Well, first we'll indent the code better than your post has it. Then ignore the numbers for now, just read the flow of the code in blocks:

Code:

#include <stdio.h>

int main ()
{
  int  line, space, asterisk;

  /* Print the first 5 lines */
  for (line = 1; line <= 9; line += 2)
  {
    /* Print a decreasing number of spaces per line */
    for (space = (9 - line) /2; space > 0; space--)
      printf (" ");
    
    /* Print an increasing number of *'s per line */
    for (asterisk = 1;  asterisk <= line;  asterisk++)
      printf("*");

    /* Move to a new line */
    printf ("\n");
  }
  
  /* Print the last 4 lines */
  for (line = 7;  line >= 0;  line -= 2)
  {
    /* Print an increasing number of spaces per line */
    for (space = (9 - line) /2; space > 0; space--)
      printf (" ");
    
    /* Print a decreasing number of *'s per line */
    for (asterisk = 1;  asterisk <= line;  asterisk++)
      printf("*");
    
    /* Move to a new line */
    printf ("\n");
  }
  
  return (0);
}

Now you can figure out how the numbers interact to print the correct format, which is the easy part.

>I didn't intend to flout your rules.
No worries, kermi3 does that every time someone forgets to use code tags.

-Prelude