On 6 July 2014 02:31, Sunita Pradhan <sunita.pradhan.2...@hotmail.com>
wrote:
> I have a set of code for count number of lines and number of words .
>
> #!/usr/bin/perl
>
> while ($line = <STDIN>){
> chomp ($line);
> $hash{L_c_start}++ if ($line =~ /^C.*/i);
> @words = split /\s+/,$line;
> *foreach $c (keys @words){*
> print "word $words[$c]\n";
> $hash{W_c_start}++ if ($words[$c] =~ /^C.*/i);
> }
> }
>
> print "$_ :: $hash{$_}\n" foreach (keys %hash);
> =========================================
>
> I want to use "while" loop instead of "foreach" . I tried it but while
> loop does not select 2nd line of <STDIN> .
>
"I tried it but while loop does not select 2nd line of <STDIN> ."
Can you show us the code after you tried that?
Why do you want to use a while loop instead of foreach?
Remember:
> while( condition ) { }
Executes the condition on each iteration, so using
> while( keys @words ) { }
means the loop will continue as long as @words returns a non-zero number of
keys.
This is different from
> for my $i ( keys @words ) { }
Where the code will be evaluated once, and the result iterated.
Though I'm not entirely understanding why you've used the unusual
> *foreach $c (keys @words){*
> print "word $words[$c]\n";
> $hash{W_c_start}++ if ($words[$c] =~ /^C.*/i);
> }
Instead of the more natural
> *foreach my $word (@words){*
> print "word $word\n";
> $hash{W_c_start}++ if ($word =~ /^C.*/i);
> }
Personally, I'd be inclined to structure code as follows if a while loop
was really wanted:
> while( @words ){
> my ($word) = shift @words;
> print "word $word\n";
> $hash{W_c_start}++ if ($word =~ /^C.*/i);
> }
And of course, standard recommendation: your code lacked 'use strict' and
'use warnings', and both are highly recommended.
--
Kentnl
