June 2018 Update

Task/Middle-three-digits/Julia/middle-three-digits.julia

@@ -1,17 +1,16 @@
-function middle(i)
-    s = string(abs(i))
+function middle3(n::Integer)
+    s = dec(abs(n))
     l = length(s)
-    mid = round(Int,(l+1)/2)
-    l < 3 ?
-        "error: not enough digits"  :
-    iseven(l) ?
-        "error: number of digits is even"  :
-    s[mid-1:mid+1]
+    if iseven(l)
+        throw(ArgumentError("n must have an odd number of digits"))
+    elseif l < 3
+        throw(ArgumentError("n must have 3 digits or more"))
+    end
+    mid = (l + 1) ÷ 2
+    return s[mid-1:mid+1]
 end
 
-julia>
-
 for n = [123, 12345, 1234567, 987654321, 10001, -10001, -123,
          -100, 100, -12345, 1, 2, -1, -10, 2002, -2002, 0]
-    println (@sprintf("%10d : ", n), middle(n))
+    @printf("%10d -> %s\n", n, try middle3(n) catch e e.msg end)
 end