What I would do is set the default value first, then try the match. Something like this:

$match = "chiapet";  # default value
if ($string =~ /foobar(...)/) {  # probably want to capture something 
+here
    $match = $1;
}
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Or the ternary ?: operator, like this:

$match = ($string =~ /foobar(...)/) ? $1 : "chiapet";
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