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Re: Pre-RFC: builtin:: functions for detecting numbers vs strings

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From:
Yuki Kimoto
Date:
March 11, 2022 23:34
Subject:
Re: Pre-RFC: builtin:: functions for detecting numbers vs strings
Message ID:
CAExogxOBncJjau=Jdr4JhFrq73+6yF4WwR7BOaMktsW0JSXD8Q@mail.gmail.com
2022-3-11 10:50 Dan Book <grinnz@gmail.com> wrote:

> On Thu, Mar 10, 2022 at 8:42 PM Darren Duncan <darren@darrenduncan.net>
> wrote:
>
>> On 2022-03-10 5:19 p.m., Yuki Kimoto wrote:
>> > I have a question.
>> >
>> > What means the scalar value is created as a number for JSON
>> serialization?
>> >
>> >    # Created as a number
>> >    my $num = 0;
>> >
>> >    # Replace 0 with "0"
>> >    $num =~ s/0/0/;
>> >    # Is this result 0 or "0"?
>> >    my $json_num = to_json $num;
>>
>> The result is absolutely certainly a string, because it is the result of
>> a
>> regular expression, which is a string operation.
>>
>> Its logically the same as if you had said:
>>
>>    my $num = ''.$num;
>>
>> So "0" is the result in $json_num.
>>
>
> To add: it is about the value being created as a string or a number, not a
> variable. The result of a s///, or any string or numeric operation, is a
> new value.
>
> -Dan
>

Darren, Dan, Yves

Thank you for telling me the difference between a variable and a value.

I have another question.

If the two "created_as_number" and "is_number" functions existed, what
cases would the two functions return the different results?

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