10.11.07

Iterators - enough of a reason for Ruby

Posted in ruby at 3:09 pm by JohnB

A non-programmer friend recently asked me why I liked Ruby so much. I asked him for a simple task that I could write in Ruby and we came up with a pyramid - from a single “a” to 26 “z”s. So I showed him this one-liner:

"a".upto("z") { |c| puts c * (1 + c[0] - "a"[0]) }

And then showed him the same program in C:

#include "stdio.h"
int main( int argc, char **argv )
{
  int loop = 0;
  for( loop = 0; loop < 26; loop++ )
  {
    int innerloop = 0;
    for( innerloop = 0; innerloop <= loop; innerloop++ )
    {
      printf( "%c", 'a' + loop );
    }
    printf("n");
  }
  return 0;
}

Enough said.

a
bb
ccc
dddd
eeeee
ffffff
ggggggg
hhhhhhhh
iiiiiiiii
jjjjjjjjjj
kkkkkkkkkkk
llllllllllll
mmmmmmmmmmmmm
nnnnnnnnnnnnnn
ooooooooooooooo
pppppppppppppppp
qqqqqqqqqqqqqqqqq
rrrrrrrrrrrrrrrrrr
sssssssssssssssssss
tttttttttttttttttttt
uuuuuuuuuuuuuuuuuuuuu
vvvvvvvvvvvvvvvvvvvvvv
wwwwwwwwwwwwwwwwwwwwwww
xxxxxxxxxxxxxxxxxxxxxxxx
yyyyyyyyyyyyyyyyyyyyyyyyy
zzzzzzzzzzzzzzzzzzzzzzzzzz

2/6/2008 Update: it might be shorter and more clear like this

("a".."z").each_with_index { |c,i| puts (c * (i + 1)) }