Online Study TokyoBouldering.js – Lingr http://lingr.com/room/tkbjs/

method.js

Function.prototype.method = function (name, func) {
	if (!this.prototype[name]) {
		this.prototype[name] = func;
		return this;
	}
};

String.method('entityify', function () {
	var character = {
		'<' : '&lt;',
		'>' : '&gt;',
		'&' : '&amp;',
		'"' : '&quot;'
	};
	return function () {
		return this.replace(/[<>&"]/g, function (c) {
			return character[c];
		});
	};
}());