Re: ensure numeric comparison

[Peng Yu]

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