相关疑难解决方法(0)

如果我创建这样的对象:

var obj = {};
obj.prop1 = "Foo";
obj.prop2 = "Bar";

生成的对象总是这样吗？

{ prop1 : "Foo", prop2 : "Bar" }

也就是说,属性是否与我添加它们的顺序相同？

是否有一种优雅的方式来访问对象的第一个属性...

1. 你不知道你的房产名称的地方
2. 不使用像for .. injQuery 那样的循环$.each

例如,我需要在foo1不知道foo1名称的情况下访问对象:

var example = {
    foo1: { /* stuff1 */},
    foo2: { /* stuff2 */},
    foo3: { /* stuff3 */}
};

我有一个来自AJAX响应的JSON数据,如下所示

    {
        "2015001":{"sname":"name1","01-07-2015":null,"02-07-2015":"0","03-07-2015":"0","04-07-2015":"0","05-07-2015":null,"06-07-2015":"0","07-07-2015":"0","08-07-2015":"0","09-07-2015":"0","10-07-2015":"0","11-07-2015":null,"12-07-2015":null,"13-07-2015":"0","14-07-2015":"1","15-07-2015":null,"16-07-2015":"2","17-07-2015":null,"18-07-2015":null,"19-07-2015":null,"20-07-2015":"2","21-07-2015":"0","22-07-2015":"0","23-07-2015":"0","24-07-2015":"1","25-07-2015":"1","26-07-2015":null,"27-07-2015":"2","28-07-2015":null,"29-07-2015":"2","30-07-2015":"2","31-07-2015":"2"},
        "2015002":{"sname":"name2","01-07-2015":null,"02-07-2015":"0","03-07-2015":"1","04-07-2015":"1","05-07-2015":null,"06-07-2015":"0","07-07-2015":"0","08-07-2015":"0","09-07-2015":"0","10-07-2015":"2","11-07-2015":null,"12-07-2015":null,"13-07-2015":"1","14-07-2015":"1","15-07-2015":null,"16-07-2015":"2","17-07-2015":null,"18-07-2015":null,"19-07-2015":null,"20-07-2015":"0","21-07-2015":"0","22-07-2015":"0","23-07-2015":"0","24-07-2015":"0","25-07-2015":"0","26-07-2015":null,"27-07-2015":"0","28-07-2015":null,"29-07-2015":"0","30-07-2015":"0","31-07-2015":"0"},
        "2015003":{"sname":"name3","01-07-2015":null,"02-07-2015":"2","03-07-2015":"2","04-07-2015":"2","05-07-2015":null,"06-07-2015":"2","07-07-2015":"2","08-07-2015":"0","09-07-2015":"2","10-07-2015":"2","11-07-2015":null,"12-07-2015":null,"13-07-2015":"2","14-07-2015":"0","15-07-2015":null,"16-07-2015":"2","17-07-2015":null,"18-07-2015":null,"19-07-2015":null,"20-07-2015":"2","21-07-2015":"2","22-07-2015":"0","23-07-2015":"2","24-07-2015":"2","25-07-2015":"2","26-07-2015":null,"27-07-2015":"2","28-07-2015":null,"29-07-2015":"2","30-07-2015":"2","31-07-2015":"2"},
        "2015004":{"sname":"name4","01-07-2015":null,"02-07-2015":"2","03-07-2015":"2","04-07-2015":"2","05-07-2015":null,"06-07-2015":"0","07-07-2015":"2","08-07-2015":"2","09-07-2015":"2","10-07-2015":"2","11-07-2015":null,"12-07-2015":null,"13-07-2015":"2","14-07-2015":"2","15-07-2015":null,"16-07-2015":"2","17-07-2015":null,"18-07-2015":null,"19-07-2015":null,"20-07-2015":"0","21-07-2015":"2","22-07-2015":"2","23-07-2015":"2","24-07-2015":"2","25-07-2015":"0","26-07-2015":null,"27-07-2015":"2","28-07-2015":null,"29-07-2015":"0","30-07-2015":"2","31-07-2015":"2"},
        "2015005":{"sname":"name5","01-07-2015":null,"02-07-2015":"2","03-07-2015":"2","04-07-2015":"0","05-07-2015":null,"06-07-2015":"2","07-07-2015":"2","08-07-2015":"2","09-07-2015":"2","10-07-2015":"2","11-07-2015":null,"12-07-2015":null,"13-07-2015":"2","14-07-2015":"2","15-07-2015":null,"16-07-2015":"2","17-07-2015":null,"18-07-2015":null,"19-07-2015":null,"20-07-2015":"0","21-07-2015":"2","22-07-2015":"2","23-07-2015":"2","24-07-2015":"2","25-07-2015":"2","26-07-2015":null,"27-07-2015":"2","28-07-2015":null,"29-07-2015":"2","30-07-2015":"2","31-07-2015":"2"},
        "2015006":{"sname":"name6","01-07-2015":null,"02-07-2015":"2","03-07-2015":"2","04-07-2015":"2","05-07-2015":null,"06-07-2015":"2","07-07-2015":"2","08-07-2015":"2","09-07-2015":"2","10-07-2015":"2","11-07-2015":null,"12-07-2015":null,"13-07-2015":"2","14-07-2015":"2","15-07-2015":null,"16-07-2015":"2","17-07-2015":null,"18-07-2015":null,"19-07-2015":null,"20-07-2015":"2","21-07-2015":"0","22-07-2015":"2","23-07-2015":"2","24-07-2015":"2","25-07-2015":"2","26-07-2015":null,"27-07-2015":"2","28-07-2015":null,"29-07-2015":"2","30-07-2015":"2","31-07-2015":"2"}
    }

每个对象具有相同数量的对象.在这里,我想计算第一个对象中的对象数量(2015001).密钥将根据每个请求进行更改.

我试过了

console.log(Object.keys(data[2015001]).length)

我得到了我需要的东西

但我怎么能没有钥匙(2015001)