There is a subtle, but important difference between
$var1 = sprintf "%.2f" => $number;
and
$var2 = int ($number * 100 + .5) / 100;
$var1 is a
PV, that is, the interval variable has a string value, but not a numeric value, while
$var2 is an
NV, that is, it has a numeric
value, but not a string value. This means that
$var1 will have two digits after the decimal point
when printed - sprintf has garanteed that. But that's not necessarely true for
$var2. Since you cannot represent
1/100 exactly in binary, you left the
possibility open that if you stringify the number, you end
up with more than 2 characters after the decimal point.
Now, it may not happen in a thousand testcases, but can you
guarantee it will never happen?
See perldoc -q decimal.
