I am not able to answer either of your questions, but I think it is significant to point out that you received a warning message, not an error message. Furthermore, you only received the warning because you wisely had warnings in effect. Had you not, your code would have silently proceeded to do something you did not intend.

One way to promote all warnings to errors is as follows: 

use warnings FATAL => 'all';

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In reply to Re: what is difference between chr and oct? by toolic
in thread what is difference between chr and oct? by xiaoyafeng

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