Encode a string flipping and rot47ing it

obfuscate-string.js

(function() {
	
	var obfuscate = {

		flip : function(x) {
			var flipped = '';
			for ( var i=(x.length)-1; i >= 0; i--) {
				flipped += x[i];
			};
			return flipped;
		},

		// http://rot47.net/_js/rot47.js
		rot47 : function(x) {
			var s = [];
			for (var i = 0; i < x.length; i ++) {
				var j = x.charCodeAt(i);
				if ((j >= 33) && (j <= 126)) {
					s[i] = String.fromCharCode(33 + ((j + 14) % 94));
				} else {
					s[i] = String.fromCharCode(j);
				}
			}
			return s.join('');
		},

		encode : function(str) {
			return this.rot47( this.flip(str) );
		},

		decode : function(str) {
			return this.flip( this.rot47(str) );
		}

	}

	String.prototype.obfuscate = function() {
		return {
			flip : obfuscate.flip(this),
			rot47 : obfuscate.rot47(this),
			encode : obfuscate.encode(this),
			decode : obfuscate.decode(this)
		}
	}

})();



var str = 'This is a sample';
var encoded = str.obfuscate().encode;
console.log( encoded );
console.log( encoded.obfuscate().decode );

// Convert to entities
function entitizy(x) {
	var out_str = '';
	for (var i = 0; i < x.length; i++) {
		out_str += '&#' + x.charCodeAt( i ) + ';';
	}
	return out_str;
}

// Custom rot31
function r(s) {
  return s.replace(/[A-Za-z0-9]/g, function (c) {
    return "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".charAt(
           "FGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyzABCDE".indexOf(c)
    );
  } );
}
console.log( r('Lorem ipsum dolor sit amet') );