javascript如何在一个对象中找到 child 的数量

Question

除了运行循环和使用计数器之外，是否有其他方法可以找到 javascript 对象中子对象的数量？如果有帮助，我可以利用 jquery。我这样做:

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);
}

Answer 1

以下在 ECMAScript5 (Javascript 1.85) 中工作

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