And I quote from perlsyn

  The foreach keyword is actually a synonym for the for keyword, so you can use foreach for readability or for for
  brevity. (Or because the Bourne shell is more familiar to you than csh, so writing for comes more naturally.) If VAR is
  omitted, $_ is set to each value. If any element of LIST is an lvalue, you can modify it by modifying VAR inside the loop.
  That's because the foreach loop index variable is an implicit alias for each item in the list that you're looping over. 

mikfire