获取对象的第一个索引 [英] Getting the first index of an object

问题描述

考虑：

var object = {
  foo: {},
  bar: {},
  baz: {}
}

我该怎么做：

var first = object[0];
console.log(first);

显然，这不起作用，因为第一个索引名为 foo ，
不是 0 。

Obviously, that doesn’t work because the first index is named foo, not 0.

console.log(object['foo']);

有效，但我不知道它的名字是foo。它可以被命名为任何东西。我只想要第一个。

works, but I don’t know it’s named foo. It could be named anything. I just want the first.

推荐答案

如果对象的顺序很重要，你应该修改你的JSON模式来存储对象在数组中：

If the order of the objects is significant, you should revise your JSON schema to store the objects in an array:

[
    {"name":"foo", ...},
    {"name":"bar", ...},
    {"name":"baz", ...}
]

或者可能：

[
    ["foo", {}],
    ["bar", {}],
    ["baz", {}]
]

正如Ben Alpert指出的那样，Javascript对象的属性是无序的，如果您希望它们按照它们在object literal - 没有first属性。

As Ben Alpert points out, properties of Javascript objects are unordered, and your code is broken if you expect them to enumerate in the same order that they are specified in the object literal—there is no "first" property.

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