http://www.perlmonks.org?node_id=524408


in reply to Re: modifying a string in place
in thread modifying a string in place

The constant form of the flip-flop only operates against $.. Ie. The line number of the current file being read. Hence the first loop below produces the output expected, but the second does not. 

#! perl -slw
use strict;

while( <DATA> ) {
    print if 1..4;
}

for ( 1 .. 8 ) {
    print if 1..4;
}


__DATA__
line 1
line 2
line 3
line 4
line 5
line 6
line 7
line 8

[download]
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In Section Seekers of Perl Wisdom