Good example of why you should always use warnings;?

$ perl -wE '$name = q(Fred); $debt = 50; say qq(You pay me ${debt}$ 00
+ cents, $name, or else!)'

Use of uninitialized value $00 in concatenation (.) or string at -e li
+ne 1.
You pay me 50 cents, Fred, or else!
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Update: Also a good demo of why interpolation can be dangerous and the case for using sprintf?

$ perl -E '$name = q(Fred); $debt = 50; say sprintf q(You pay me %s$ 0
+0 cents, %s, or else!), $debt, $name'

You pay me 50$ 00 cents, Fred, or else!
[download]