javascript如何查找对象中的子代数 [英] javascript how to find number of children in an object

问题描述

除了运行循环和使用计数器外，还有没有其他方法可以找到javascript对象中的子代数?如果有帮助，我可以利用jquery.我正在这样做:

is there a way to find the number of children in a javascript object other than running a loop and using a counter? I can leverage jquery if it will help. I am doing this:

var childScenesObj = [];
var childScenesLen = scenes[sceneID].length; //need to find number of children of scenes[sceneID]. This obviously does not work, as it an object, not an array.


for (childIndex in scenes[sceneID].children) {
    childSceneObj = new Object();
    childSceneID = scenes[sceneID].children[childIndex];
    childSceneNode = scenes[childSceneID];
    childSceneObj.name = childSceneNode.name;
    childSceneObj.id = childSceneID;
    childScenesObj  .push(childSceneObj);
}

推荐答案

以下内容在ECMAScript5(Javascript 1.85)中起作用

The following works in ECMAScript5 (Javascript 1.85)

var x = {"1":1, "A":2};
Object.keys(x).length; //outputs 2

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