For questions about Perl core syntax
Questions tagged [perlsyn]
6 questions
10
votes
6 answers
foreach my $var (@list) -- $var is a reference?
So, I never knew this and I want to get some clarifcation on it. I know if you do
foreach (@list){
if you change $_ in that loop it will affect the actual data. But, I did not know that if you did
foreach my $var1 (@list){
If you changed $var1 in…
Ryan Detzel
- 5,519
- 9
- 37
- 49
8
votes
3 answers
Why does Perl warn about "useless constant 1" when using bigint?
I was writing a module as part of my application when I noticed syntax check results in warning about useless use of a constant (1). Why is that?
The constant is the obligatory 1 at the end of the module which is normally ignored by warnings as…
Daniel Böhmer
- 14,463
- 5
- 36
- 46
4
votes
3 answers
Perl - pass code block as parameter inside parentheses
Is it possible to pass a block of code to a sub using "parentheses" syntax?
I.e. when i write
List::MoreUtils::any { defined ($_) } (undef, undef, 1);
it works. But when i try to add parentheses
List::MoreUtils::any ( { defined ($_) } , (undef,…
ivan_pozdeev
- 33,874
- 19
- 107
- 152
2
votes
3 answers
Scope of the default variable $_ in Perl
I have the following method which accepts a variable and then displays info from a database:
sub showResult {
if (@_ == 2) {
my @results = dbGetResults($_[0]);
if (@results) {
foreach (@results) {
…
skeniver
- 2,647
- 6
- 28
- 34
1
vote
3 answers
Meaning of the perl syntax construction involving a comma
I've encountered a piece of code in a book that looks like this:
#for (some_condition) {
#do something not particularly related to the question
$var = $anotherVar+1, next if #some other condition with $var
#}
I've got no clue what does the comma…
Ivan
- 163
- 1
- 12
1
vote
7 answers
Perl for loop explanation
I'm looking through perl code and I see this:
sub html_filter {
my $text = shift;
for ($text) {
s/&/&/g;
s//>/g;
s/"/"/g;
}
return $text;
}
what does the for loop do in this…
Timmy
- 12,468
- 20
- 77
- 107