Nodejs Utililty Methods String Hash

String.prototype.multiReplace = function ( hash ) {
    var str = this, key;
    for ( key in hash ) {
        if ( Object.prototype.hasOwnProperty.call( hash, key ) ) {
            str = str.replace( new RegExp( key, 'g' ), hash[ key ] );
    return str;

String.prototype.parseHashtag = function() {
  return this.replace(/[#]+[A-Za-z0-9-_]+/g, function(t) {
    var tag = t.replace("#","%23")
    return t.link("http://search.twitter.com/search?q="+tag);
  });
};

String.prototype.parseHashtag = function() {
  return this.replace(/[#]+[A-Za-z0-9-_]+/g, function(t) {
    var tag = t.replace("#","%23")
    return t.link("https://twitter.com/hashtag/"+tag+"?src=hash");
  });
};

String.prototype.parseHashtag = function() {
  return this.replace(/[#]+[A-Za-z0-9-_]+/, function(t) {
    var tag = t.replace("#","%23")
    return t.link("http://search.twitter.com/search?q="+tag);
  });
};

String.prototype.parseHashtag = function() {
    return this.replace(/[#]+^[ ,,]+/g, function(t) {
        var tag = t.replace("#","%23")
        return t.link("http://search.twitter.com/search?q="+tag);
    });
};
test = "Simon is writing a post about #??, #?? #and parsing hashtags as URLs";
document.writeln(test.parseHashtag());

String.prototype.stripHashtag = function() {
    return this.replace(/[#]+[A-Za-z0-9-_]+/g, "");
};

String.prototype.toHash = function () {
  return this.split('').reduce((a, b) => {
    a = ((a << 5) - a) + b.charCodeAt(0)
    return a & a
  }, 0)

String.prototype.toHashCode = function toHashCode() {
  let hash = 0;
  for (let i = 0; i < this.length; i++) {
    hash = ((hash << 5) - hash) + this.charCodeAt(i);
    hash |= 0; 
  return hash;