Simple JavaScript in-page counter

counter.js

var Counter = {
	_c: {},
	get: function(c) { return Counter._c[c] || 0; },
	set: function(c, v) { Counter._c[c] = v; return v; },
	inc: function(c, v) { return Counter.set(c, Counter.get(c) + (v || 1)); },
	dec: function(c, v) { return Counter.inc(c, (v ? -v : -1)); }
};

/**
 * Usage:
 *   Counter.get("x")     ->  0
 *   Counter.inc("x")     ->  1
 *   Counter.inc("x", 2)  ->  3
 *   Counter.dec("x")     ->  2
 *   Counter.set("x", 5)  ->  5
 *   Counter.get("x")     ->  5
 */