Show week number with Javascript?

Question

I have the following code that is used to show the name of the current day, followed by a set phrase.

<script type="text/javascript">      <!--      // Array of day names     var dayNames = new Array(     "It's Sunday, the weekend is nearly over",     "Yay! Another Monday",      "Hello Tuesday, at least you're not Monday",      "It's Wednesday. Halfway through the week already",      "It's Thursday.",      "It's Friday - Hurray for the weekend",     "Saturday Night Fever");     var now = new Date();     document.write(dayNames[now.getDay()] + ".");      // --> </script> 

What I would like to do is have the current week number in brackets after the phrase. I have found the following code:

Date.prototype.getWeek = function() {     var onejan = new Date(this.getFullYear(),0,1);     return Math.ceil((((this - onejan) / 86400000) + onejan.getDay()+1)/7); }  

Which was taken from http://javascript.about.com/library/blweekyear.htm but I have no idea how to add it to existing javascript code.

Answer 1

Simply add it to your current code, then call (new Date()).getWeek()

<script>     Date.prototype.getWeek = function() {         var onejan = new Date(this.getFullYear(), 0, 1);         return Math.ceil((((this - onejan) / 86400000) + onejan.getDay() + 1) / 7);     }      var weekNumber = (new Date()).getWeek();      var dayNames = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];     var now = new Date();     document.write(dayNames[now.getDay()] + " (" + weekNumber + ")."); </script>