CODEWITHSUNDEEP
perlhash
NinjaAnte
NinjaAnte

Reputation: 23

Print keys and values from hash in a proper format?

Hello I am trying to print the values and keys of a hash with one key/value per row like this:

key:value

This is the code I am using to print my hash:

foreach (sort keys %hash) { print "$_:$hash{$_}\n"; }

And this is the output I get:

key
:value

Why is my script printing the value on a new row and what can I do to fix it?

Upvotes: 1

Views: 865

Answers (2)

Dfr
Dfr

Reputation: 4175

Try this version of printing loop:

foreach (sort keys %hash) {
   my $v = $hash{$_};
   s/\s+$//;
   print "$_:$v\n";
}

Keys in %hash definitely have some unwanted trailing characters, so it is better to filter them out when %hash is filled. For example instead of this:

@hash{@keys} = @vals;

Write this:

@hash{map { s/\s+$//; $_ } @keys} = @vals;

Or this:

chmop(@keys);
@hash{@keys} = @vals;

But chomp will not help with multiple characters.

Upvotes: -2

ikegami
ikegami

Reputation: 385809

The cursor is moving to the next line because your key contains a line feed. The solution is to remove the line feed from the key.

More specifically, you surely want to avoid creating a key with a line feed in the first place, so it should be removed from the key before you create the hash element.

You're presumably reading the key from a file handle. It's customary to use chomp (to remove any trailing line feed) or s/\s+/z// (to remove any trailing whitespace including line feeds).

my @keys;
while (<>) {
   chomp;         # Or: s/\s+\z//;
   push @keys, $_;
}

my %hash; @hash{@keys} = @values;

Upvotes: 1

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