pad-month.xquery

(:~
: Neat examples of zero-padding a one digit month, for later
: construction of xs:date etc.
:)


(: Example 1: When given a single digit month :)
let $month := '4'
return
  substring(concat('0', $month), string-length($month))

(: Example 2: When given a double digit month :)
let $month := '19'
return
  substring(concat('0', $month), string-length($month))

(: Example 3: suggested by @nine9ths 2014-04-28 :)
concat(('0')[string-length($month)], $month)
  
(: Example 4: Suggested by @michaelhkay 2014-04-28 :)
substring(string(100 + number($month), 2)

So far I like @michaelhkay's approach best

these algorithms + a few more as a page in my cookbook http://kitwallace.co.uk/Book/set/zero-pad/page

The timings are all about the same and a better test here I think is how underatnable the code is, perhaps measured by quickly a reader can mentally verify that the code does what it intends to do. I should add voting to the website.