Javascript Javascript获取对象中项目列表的长度？
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Javascript Get length of list of items in object?
提问by user3802348
I currently have a Javascript object that looks like this:
我目前有一个如下所示的 Javascript 对象：
Object {0: 8, 1: 9, 2: 10}
Object {0: 8, 1: 9, 2: 10}
I am trying to get the number of individual items in the object (i.e. 3) but can't figure out how to do so. Since the object isn't an array, I can't just call .length(). I tried huntsList[2].toString().split('.').lengthto split the items at the commas and count them in this way but it returns 1, since it converts the entire object to a single string that looks like this: ["[object Object]"].
我正在尝试获取对象中单个项目的数量（即 3），但不知道该怎么做。由于对象不是数组，我不能只调用.length(). 我试图huntsList[2].toString().split('.').length在逗号分割的项目，这样算来，但它返回1，因为它整个对象转换为一个字符串，看起来像这样：["[object Object]"]。
Any suggestions for how I can accomplish this are appreciated.
任何关于我如何实现这一点的建议表示赞赏。
回答by omarjmh
回答by dork
You can use Object.keys(). It returns an array of the keys of an object.
您可以使用Object.keys(). 它返回一个对象键的数组。
var myObject = {0: 8, 1: 9, 2: 10};
console.log(Object.keys(myObject).length)
回答by TMB
1: ES5.1 solution use Object.keys - returns an array of a given object's own enumerable properties
1：ES5.1 解决方案使用 Object.keys - 返回给定对象自身可枚举属性的数组
var obj = {
0: 8,
1: 9,
2: 10
}
console.log(Object.keys(obj).length)2: Pre-ES5 Solution: use for..in and hasOwn
2：ES5 之前的解决方案：使用 for..in 和 hasOwn
var obj = {
0: 8,
1: 9,
2: 10
};
var propsLength = 0;
for (prop in obj) {
if (obj.hasOwnProperty(prop)) {
propsLength = propsLength + 1;
}
}
console.log(propsLength);3: Library Solution: Use lodash/underscore Convert it to an array, and query its length, if you need a pure js solution, we can look into how toArray works.
3：库解决方案：使用lodash/underscore将其转换为数组，并查询其长度，如果需要纯js的解决方案，我们可以看看toArray是如何工作的。
console.log(_.toArray({
0: 8,
1: 9,
2: 10
}).length)<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore.js"></script>回答by sudhakar phad
var obj = {0: 8, 1: 9, 2: 10};
alert(Object.keys(obj).length);
with this code, try to alert the length of you object mate.!
使用此代码，尝试提醒您对象的长度。！
