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.




middleThree: function [num][
    n: to :string abs num
    if 3 > size n -> return "Number must have at least three digits"
    if even? size n -> return "Number must have an odd number of digits"
 
    middle: ((size n)/2)- 1 
    return slice n middle middle+2
]
 
samples: @[ 
    123, 12345, 1234567, 987654321, 10001, neg 10001, neg 123, neg 100, 100, neg 12345,
    1, 2, neg 1, neg 10, 2002, neg 2002, 0 
]
 
loop samples 's [
    print [pad to :string s 10 ":" middleThree s]
]