Task

Write a function/procedure/subroutine that is called with an integer value and returns the middle three digits of the integer if possible or a clear indication of an error if this is not possible.

Note: The order of the middle digits should be preserved.

Your function should be tested with the following values; the first line should return valid answers, those of the second line should return clear indications of an error:

123, 12345, 1234567, 987654321, 10001, -10001, -123, -100, 100, -12345
1, 2, -1, -10, 2002, -2002, 0

Show your output on this page.




func middle_three(n) {
  var l = n.len;
  if (l < 3) {
    "#{n} is too short"
  } elsif (l.is_even) {
    "#{n} has an even number of digits"
  } else {
    "The three middle digits of #{n} are: " + n.digits.ft(l-3 / 2, l/2 + 1).join
  }
}
 
var nums = %n(
    123 12345 1234567 987654321 10001 -10001 -123 -100 100 -12345
    1 2 -1 -10 2002 -2002 0
);
nums.each { say middle_three(_) };