function empty(a) {
	if (a === "" || a === 0 || a === null || a === 'null' || a === 'undefined' || a === !1 || typeof a === "undefined") return !0;
	if (typeof a === "object") if (a instanceof Array) return a.length === 0;
	else {
		for (var b in a) return !1;
		return !0
	}
	if (typeof a === "string") return a.length === 0
}

//it detects any type of empty var in JS like array, object, string, number etc..

detect any type of empty var in JS

JavaScript