quotation mark as key

[ic23oluk]

hello monks

is it possible to assing a hash with a quote sign as keys? i.e.  my $hash = (""" => 1) The reason for my question is I try to assing hash harboring the ascii signs as keys, and the corresponding numbers as values

[Corion]

First off, if you are using a hash reference, you need braces, not parentheses:

my $hash = {
    foo => 'bar',
};

There are several approaches you can use.

Use single quotes for a double quote:

my $hash = {
    '"' => 1,
};

Quote the double quote:

my $hash = {
    "\"" => 1,
};

Use chr:

my $hash = {
    chr(34) => 1,
};

Use alternative quotes:/p>

my $hash = {
    q(") => 1,
};

[roboticus]

ic23oluk:

Sure, you can do that:

my %t = ('"'=>1);

You just have to either escape it correctly or use alternative quoting mechanisms.

However, making a hash to hold a character and it's corresponding ASCII value isn't necessary since the ord function will give you the ASCII value for an ASCII character.

...roboticus

When your only tool is a hammer, all problems look like your thumb.

[huck]

Yes, but your hash assignment and scalar constant are wrong.

use strict; use warnings; 
use Data::Dumper; 
my $hash = {"\"" => 1,':'=>2}; 
print Dumper($hash);

Any characters can be used in keys, but the scalar constants must be quoted/escaped properly when using one to assign the key.

[kcott]

G'day ic23oluk,

I see you've been given lots of advice on how to handle that specific character.

From your question, it appears that you may be attempting to hard-code each character and ASCII value. That's a lot of effort, and quite unnecessary, for your stated task: "ascii signs as keys, and the corresponding numbers as values". You can do that with a single statement:

my %hash = map { chr $_ => $_ } 32 .. 126;

That will give you a table of all, printable, 7-bit ASCII characters and their corresponding decimal values. You can test it like this:

$ perl -e 'use Data::Dump; my %h = map { chr $_ => $_ } 32 .. 126; dd 
+\%h'
{
  " "  => 32,
  "!"  => 33,
  "\"" => 34,
...
  "|"  => 124,
  "}"  => 125,
  "~"  => 126,
}

Take a look at sprintf, if you want to format the values as hexadecimal, Unicode code points, HTML entity references, or something else. For example,

$ perl -e 'use Data::Dump; my %h = map { chr $_ => sprintf "U+%04X", $
+_ } 32 .. 126; dd \%h'
{
  " "  => "U+0020",
  "!"  => "U+0021",
  "\"" => "U+0022",
...
  "|"  => "U+007C",
  "}"  => "U+007D",
  "~"  => "U+007E",
}

[Aside: I'm guessing English isn't your first language. The word you were looking for in your OP is "assign" ('n' and 'g' order reversed). The word "assing" means something else: I'll leave you to follow that link if want a chuckle. :-)]