Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
446 views
in Technique[技术] by (71.8m points)

hashref - Perl access value from Hash Reference

In my Perl code, I ended up having a hash reference like below. I would like to access an individual element from it. I tried multiple ways, but I was not able to fetch it.

#!/usr/bin/perl
#use strict;
use Data::Dumper;
my %h={'one'=>1,'two'=>2};
print Dumper($h{'one'});

Output

$VAR1 = undef;
question from:https://stackoverflow.com/questions/66062880/perl-access-value-from-hash-reference

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

Use parentheses to construct your hash, not braces:

use strict;
use warnings;
use Data::Dumper;

my %h = ('one'=>1, 'two'=>2);
print Dumper($h{'one'});

Braces are used to construct a hash reference.

Also, add use warnings;, which would have generated a message that there was a problem with your code.


Or, if you really wanted a hashref:

my $h = {'one'=>1, 'two'=>2};
print "$h->{one}
";

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...