Javascript String formatDate()

'use strict';//w  ww.  ja  v a2  s. c  o  m
var moment = moment || {};

String.prototype.formatDate = function () {
    return moment(this.toString()).format('LL');
};

String.prototype.formatDate = function() {
    var pattern = new RegExp("^(\\d{4})(\\d{2})(\\d{2})$");
    var match = pattern.exec(this);
    if (match && match[1] && match[2] && match[3]) {
        return match[1] + "-" + match[2] + "-" + match[3];
    }//from  w  ww  .ja  v  a2  s  .  co  m
    return this;
};