Let's analyze it. @a is an array of strings. Next, you iterate over it with
foreach $key (@a)

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So, $key is a string, "Mon" in the first iteration. Then, you use the expression
${$key}[0]

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It tries to dereference $key as an array reference, but it is not: it is a scalar string. Hence the error.
لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

In reply to Re: Cant use string(_) as array ref..!! by choroba
in thread Cant use string(_) as array ref..!! by reaper9187

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