How can I apply the flag value to all the values in the rest of the array.

What is a "flag value" and how can you apply it on something?

In order for it to work correctly, it looks like I need to use it as a string array.

Perl doesn't know "string" arrays. Perl has scalars, and will make it act as a number if you use it as a number, and will make it act as a string if you use it as a string.

-0 as a string consists of two characters, the first a minus symbol, the second a zero. -0 as a number is the same as 0.

Abigail