Re: ensure numeric comparison

[Peng Yu]

But my question involves empty string which is "unassigned". It is not
explained in the 3x3 table in that section.

On 5/7/22, david kerns <david.t.kerns@gmail.com> wrote:
> see 6.3.2.1 String Type versus Numeric Type
> in https://www.gnu.org/software/gawk/manual/gawk.html
>
> On Fri, May 6, 2022 at 9:44 PM Peng Yu <pengyu.ut@gmail.com> wrote:
>
>> Is there a test case for which `awk -e '{ print ($1 < $2) }' < input`
>> can not compare $1 and $2 numerically given the input columes 1 and 2
>> are numbers or empty strings?
>>
>> On 5/6/22, david kerns <david.t.kerns@gmail.com> wrote:
>> > pretty sure the only way to guarantee numeric comparison is to add 0
>> >
>> > awk -e '{ print ($1 +0 < $2 + 0) }' < input
>> >
>> > (not sure if it's required on both sides, but it can't hurt)
>> >
>> > On Fri, May 6, 2022 at 3:28 PM Peng Yu <pengyu.ut@gmail.com> wrote:
>> >
>> >> Hi,
>> >>
>> >> I want to make sure whether the following code is guaranteed to
>> >> compare $1 and $2 numerically as long as the input of the 1st and 2nd
>> >> fields are legitimate numbers or empty strings (which are considered
>> >> as 0).
>> >>
>> >> awk -e '{ print ($1 < $2) }' < input
>> >>
>> >> Or there is any corner case when even the 1st and 2nd fields are
>> >> legitimate numbers or empty strings, they may be compared as strings.
>> >>
>> >> Note although an empty string compared with an empty string is a
>> >> string comparison, the result is the same as 0 and 0 comparison, so it
>> >> is still effectively considered as a numerical comparison for the
>> >> current discussion.
>> >>
>> >> --
>> >> Regards,
>> >> Peng
>> >>
>> >>
>> >
>>
>>
>> --
>> Regards,
>> Peng
>>
>


-- 
Regards,
Peng