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.




middle3 = function(num)
    if num < 0 then num = -num
    s = str(num)
    if s.len < 3 then return "Input too short"
    if s.len % 2 == 0 then return "Input length not odd"
    mid = (s.len + 1) / 2 - 1
    return s[mid-1:mid+2]
end function
 
for test in [123, 12345, 1234567, 987654321, 10001, -10001, -123, -100,
 100, -12345, 1, 2, -1, -10, 2002, -2002, 0]
    print test + " --> " + middle3(test)
end for