Convert numbers from 1 to 999999 into german strings. Script should prompt for a number and show result using an JavaScript-alert. Must run in Chrome out of the box, just by loading the HTML file.

human_nr.html

<pre>
<script>

function human_nr(n){
  // Make `prompt` and `alert` no-ops when run in test mode
  prompt = function() { return n };
  alert = function() {};

  // To extract the bare, minimized, executable script: 
  //  * Copy the lines between the markers into a new file
  //  * Surround with script tag.
  //
  // To determine the size of the extracted script:
  //  * Count the number of characters between the markers (including the
  //    final newline). Make sure that UTF-8 multibyte characters are counted
  //    as one character, not as several bytes. TextMate’s Ctrl-n will count
  //    bytes – use eg. `wc -m` instead.
  //  * Add 16 to account for script tags and removal of final newline.
  //
  // Currently, there are 358 characters between the markers, so the extracted
  // script will be 374 characters long.
  //
  // See also: 
  //  * https://github.com/catearcher/HumanNumbers 
  //  * https://gist.github.com/neuling/6334065
  //
// ---8<---8<---8<---8<---8<---8<---8<---
n=prompt(T="0Xn0zwX0drX0vier0fünf0sechs0sieben0acht0neun0z0(en|s)z0zehn0Y0ei0X0elf0XnY0zwölf0zwXY0wanz0wXß0Xßi0Xzi0Xns0Xn$0Y0Xnzig00^t.+?d".split(0))
function d(n){r=T[n/100%10^0]
r+=(r?"hundert":"")+T[n%10]
n%=100
return r+(r&&n>19?"und":"")+(n>9?T[n/10^0]+"zig":"")}r=d(n/1e3^0)+"tausend"+d(n)
for(i=29;i>9;)r=r.replace(RegExp(T[i--],"g"),T[i--])
alert(r)
// ---8<---8<---8<---8<---8<---8<---8<---
  return r
};

var good = 0, bad = 0;

assert(1, "eins");
assert(2, "zwei");
assert(3, "drei");
assert(4, "vier");
assert(5, "fünf");
assert(6, "sechs");
assert(7, "sieben");
assert(8, "acht");
assert(9, "neun");
assert(10, "zehn");
assert(11, "elf");
assert(12, "zwölf");
assert(13, "dreizehn");
assert(14, "vierzehn");
assert(16, "sechzehn");
assert(17, "siebzehn");
assert(18, "achtzehn");
assert(19, "neunzehn");
assert(20, "zwanzig");
assert(21, "einundzwanzig");
assert(22, "zweiundzwanzig");
assert(27, "siebenundzwanzig");
assert(30, "dreißig");
assert(31, "einunddreißig");
assert(40, "vierzig");
assert(42, "zweiundvierzig");
assert(50, "fünfzig");
assert(53, "dreiundfünfzig");
assert(60, "sechzig");
assert(64, "vierundsechzig");
assert(70, "siebzig");
assert(77, "siebenundsiebzig");
assert(80, "achtzig");
assert(88, "achtundachtzig");
assert(90, "neunzig");
assert(99, "neunundneunzig");
assert(100, "einhundert");
assert(101, "einhunderteins");
assert(107, "einhundertsieben");
assert(112, "einhundertzwölf");
assert(117, "einhundertsiebzehn");
assert(181, "einhunderteinundachtzig");
assert(200, "zweihundert");
assert(267, "zweihundertsiebenundsechzig");
assert(700, "siebenhundert");
assert(766, "siebenhundertsechsundsechzig");
assert(999, "neunhundertneunundneunzig");
assert(1000, "eintausend");
assert(1001, "eintausendeins");
assert(1011, "eintausendelf");
assert(1555, "eintausendfünfhundertfünfundfünfzig");
assert(1990, "eintausendneunhundertundneunzig");
assert(2500, "zweitausendfünfhundert");
assert(10000, "zehntausend");
assert(11111, "elftausendeinhundertelf");
assert(69666, "neunundsechzigtausendsechshundertsechsundsechzig");
assert(100000, "einhunderttausend");
assert(100001, "einhunderttausendeins");
assert(101001, "einhunderteintausendeins");
assert(111111, "einhundertelftausendeinhundertelf");
assert(218519, "zweihundertachtzehntausendfünfhundertneunzehn");
assert(878777, "achthundertachtundsiebzigtausendsiebenhundertsiebenundsiebzig");
assert(999999, "neunhundertneunundneunzigtausendneunhundertneunundneunzig");

function assert(nr, expected) {
  var result = human_nr(nr);
  if (result == expected) {
    good++;
    return;
  }
  bad++;
  document.write("FAILED: Expected c(<b>" + nr + "</b>) to return '<b>" + expected + "</b>', got '<b>" + result + "</b>'.\n");
}
document.write("\n\n<b style='color: #090'>" + good + " good</b>, <b style='color: #900'>" + bad + " bad.</b>");
</script>