I suspect you can assign 1 to it, but other values are silently ignored

You suspect incorrectly. 

$ perl -e '@array=(qw(ant bat cat)); $[ = 94; print $array[95]."\n"'
bat

$ perl -e '@array=(qw(ant bat cat)); $[ = -9; print $array[-8]."\n"'
bat

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In reply to Re^3: how internally $#array is working in Perl by DrHyde
in thread how internally $#array is working in Perl by kiruthika.bkite

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