Thanks Dermot and erez.schatz I got it ~ On Tue, Dec 8, 2009 at 4:59 PM, Erez Schatz <moonb...@gmail.com> wrote:
> 2009/12/8 Majian <jian...@gmail.com>: > > my $s = "The black cat jumped from the green tree"; > > print index $s, "e", 3 ####The result is 18 > > It's slightly confusing, but if you get the idea behind it, it's > actually very simple: > > counting from 0, the string "The black cat jumped from the green tree" > has an 'e' at the 2nd position, then at the 18th position. You > specified 3 as the start position, so index ignores the e at the 2nd > position, and returns the first 'e' it finds, at the 18th position. > > I'm assuming you expected 14, however, the real index is better, since > in future reference to the string, you don't need to recall where you > started the original index count, then redo some calculations etc. > whenever you need to refer to that 'e' all you now need is that it's > actual position in the string > > -- > Erez > > "The government forgets that George Orwell's 1984 was a warning, and > not a blueprint" > http://www.nonviolent-conflict.org/ -- http://www.whyweprotest.org/ >
