Nodejs Utililty Methods String Replace

String.prototype.replaceEntities = function () {
  return this.replace(/\s*<br>\s*/g, '\n').replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/ +(?= )/g, '').replace('&lt;b&gt;','\n<b>').replace('&lt;/b&gt;','</b>');
};

String.prototype.replaceExtension = function (newExtension) {
  return this.substring(0, this.lastIndexOf('.')) + newExtension;

String.prototype.replaceFromObj = function(obj) {
  var retStr = this;
  for (var x in obj) {
  if(obj.hasOwnProperty(x)){
    retStr = retStr.replace(new RegExp(x, 'g'), obj[x]);
  return retStr;
};
...

String.prototype.replaceHtmlEntites = function() {
  var translate_re = /&(nbsp|amp|quot|lt|gt);/g;
  var translate = {'nbsp': ' ', 'amp' : '&', 'quot': '\'','lt'  : '<','gt'  : '>'};
  return (this.replace(translate_re, function(match, entity) {
    return translate[entity];
  }));
};

String.prototype.replaceKeywords = function(replacements){
  var str = this;
  for(var key in replacements){
    str = str.replaceAll(key, replacements[key]);
  return str;
};

String.prototype.replaceLast = function (what, replacement) {
    return this.reverse().replace(new RegExp(what.reverse()), replacement.reverse()).reverse();
};

String.prototype.replaceList=function(c,i,s){
  s=s||',';
  var ret=this.split(s);
  ret[i-1]=c;
  return ret.join(s);

var text = 'Write a&nbspfunction&nbspthat&nbspreplaces non breaking&nbsp&nbspwhite-spaces in a&nbsptext with&nbsp.';
String.prototype.replaceNbsp = function () {
    return this.replace(/&nbsp/g, ' ');
console.log(text.replaceNbsp());

String.prototype.replaceNewAll = function(str1, str2, ignore) 
  return this.replace(new RegExp(str1.replace(/([\/\,\!\\\^\$\{\}\[\]\(\)\.\*\+\?\|\<\>\-\&])/g,"\\$&"),(ignore?"gi":"g")),(typeof(str2)=="string")?str2.replace(/\$/g,"$$$$"):str2);

String.prototype.replaceNewLineChars = function( replacement )
  return this.replace( /\n/g, replacement ) ;