//沒有檢測繼承屬性
function isEmptyObj(obj){
    for(var i in obj){
        if(i){
            return false;
        }
    }
    return true;
}

var a = {name:"aa"};
function p(){}
p.prototype.name = "aa";

console.log(isEmptyObj(a)); // ==> false
console.log(isEmptyObj(new p())); // ==> false

//檢測繼承屬性
function isEmptyObj(obj){
    for(var i in obj){
        if(obj.hasOwnProperty(i)){
            if(i){
                return false;
            }
        }
    }
    return true;
}

var a = {name:"aa"};
function p(){}
p.prototype.name = "aa";

console.log(isEmptyObj(a)); // ==> false
console.log(isEmptyObj(new p()));   // ==> true