json-enumerable-defineproperties.js

var C = function C(a,b) {
	this.a = a||'';
	this.b = b||'';
};

Object.defineProperties(C.prototype,{
	a: {
		configurable: true,
		enumerable: true,
		get: function() {
			return this._a;
		},
		set: function(v) {
			if ( typeof v === 'undefined' || v === null ) {
				v = '';
			}
			v += '';
			this._a = v.toLowerCase();
		}
	},
	_a: {
		configurable: false,
		enumerable: false,
		writable: true,
		value: ''
	},
	b: {
		configurable: true,
		enumerable: true,
		writable: true,
		value: ''
	}
});

var c = new C('HELLO','WORLD');
console.log('c instance object: ',c);
console.log('c._a enumerable? %s',c._a.propertyIsEnumerable());
console.log('c as stringified JSON: %s',JSON.stringify(c));