javascript通过对象递归 [英] javascript recursive through an object
问题描述
出于调试和日志记录的原因,我想递归地遍历一个对象.但我的实际代码片段在第一个对象之后中断.
I want to step recursively through an object for debugging and logging reasons. But my actual code snippet breaks after the first object.
function showData(obj)
{
for(var key in eval(obj))
{
debugWriteLine('object = '+obj+' | property = '+key+' | type = '+typeof(eval(obj+'.'+key))+' | value = '+eval(obj+'.'+key));
if(typeof(eval(obj+'.'+key))=== 'object')
{
obj= obj+'.'+key;
return showData(obj);
}
}
}
showData('$');
这仅显示了 $ 和 $.fn 的内容,但我需要 $ 的所有属性.
This showed me only the content of $ and $.fn but I need all the properties of $.
谢谢弗洛里安
推荐答案
第一:您既不需要也不想要 eval
来实现这些.从 $
(对象)开始,然后在查看其属性之一时使用 obj[key]
.当该属性是非函数对象时递归.
First: You neither need nor want eval
for any of this. Start with $
(the object) and then use obj[key]
when you are looking into one of its properties. Recurse when that property is a non-function object.
您没有看到所有属性的原因是 for-in
循环仅遍历 enumerable 属性,而 jQuery 的许多属性是不可枚举的.您可以使用 getOwnPropertyNames
来获取对象的所有字符串键属性的名称,甚至是不可枚举的.您可以使用 getPrototypeOf
获取该对象的原型,以便枚举其属性(for-in
可以这样做).
The reason you're not seeing all of the properties is that for-in
loops only loop through enumerable properties, and many of jQuery's properties are not enumerable. You can use getOwnPropertyNames
to get the names of all string-keyed properties of an object, even non-enumerable ones. And you can use getPrototypeOf
to get that object's prototype so you can enumerate its properties (which for-in
does).
所以:
function showData(name, obj)
{
while (obj && obj != Object.prototype)
{
// Get all of the object's property names, even non-enumerable ones
var keys = Object.getOwnPropertyNames(obj);
keys.forEach(function(key)
{
// We should restrict this check to function objects; left
// as an exercise for the reader...
if (key !== "caller" &&
key !== "callee" &&
key !== "arguments"
)
{
var value = obj[key];
var type = typeof value;
debugWriteLine('object = ' + name + ' | property = ' + key + ' | type = ' + type + ' | value = ' + value);
if (type === 'object')
{
return showData(name + "." + key, value);
}
}
});
// Get the object's prototype
obj = Object.getPrototypeOf(obj);
}
}
现场示例:
var debugWriteLine = console.log.bind(console);
function showData(name, obj)
{
while (obj && obj != Object.prototype)
{
// Get all of the object's property names, even non-enumerable ones
var keys = Object.getOwnPropertyNames(obj);
keys.forEach(function(key)
{
// We should restrict this check to function objects; left
// as an exercise for the reader...
if (key !== "caller" &&
key !== "callee" &&
key !== "arguments"
)
{
var value = obj[key];
var type = typeof value;
debugWriteLine('object = ' + name + ' | property = ' + key + ' | type = ' + type + ' | value = ' + value);
if (type === 'object')
{
return showData(name + "." + key, value);
}
}
});
// Get the object's prototype
obj = Object.getPrototypeOf(obj);
}
}
showData('$', $);
.as-console-wrapper {
max-height: 100% !important;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
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