How to get the day of the week from the day number in JavaScript?

Question

Given dayNumber is from 0 - 6 representing Monday - Sunday respectively.

Can the Date /

Answer 1

This will add a getDayOfWeek() function as a prototype to the JavaScript Date class.

Date.prototype.getDayOfWeek = function(){   
    return ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"][ this.getDay() ];
};