如何销毁 JavaScript 对象？

最近，我发现我的一个应用程序消耗了太多的内存，并且每秒增加了10 MB。

所以，我想知道如何破坏 JavaScript 对象和变量，使内存消耗停留下来，我的 FF 不能被销毁。

我调用我的两个脚本每8秒不重新加载页面。

function refresh() {
$('#table_info').remove();
$('#table').hide();
if (refreshTimer) {
clearTimeout(refreshTimer);
refreshTimer = null ;
}
document.getElementById('refresh_topology').disabled=true;
$('<div id="preload_xml"></div>').html('<img src="pic/dataload.gif" alt="loading data" /><h3>Loading Data...</h3>').prependTo($("#td_123"));
$("#topo").hide();
$('#root').remove();
show_topology();
}

我怎样才能知道是哪个变量导致了 内存开销，是什么方法停止了这个过程的执行？

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Structure your code so that all your temporary objects are located inside closures instead of global namespace / global object properties and go out of scope when you've done with them. GC will take care of the rest.

小开

You can't delete objects, they are removed when there are no more references to them. You can delete references with delete.

However, if you have created circular references in your objects you may have to de-couple some things.

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最佳答案

You could put all of your code under one namespace like this:

var namespace = {};


namespace.someClassObj = {};


delete namespace.someClassObj;

Using the delete keyword will delete the reference to the property, but on the low level the JavaScript garbage collector (GC) will get more information about which objects to be reclaimed.

You could also use Chrome Developer Tools to get a memory profile of your app, and which objects in your app are needing to be scaled down.

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I was facing a problem like this, and had the idea of simply changing the innerHTML of the problematic object's children.

adiv.innerHTML = "<div...> the original html that js uses </div>";

Seems dirty, but it saved my life, as it works!

小开

While the existing answers have given solutions to solve the issue and the second half of the question, they do not provide an answer to the self discovery aspect of the first half of the question that is in bold:

"How can I see which variable causes memory overhead...?"

It may not have been as robust 3 years ago, but the Chrome Developer Tools "Profiles" section is now quite powerful and feature rich. The Chrome team has an insightful article on using it and thus also how garbage collection (GC) works in javascript, which is at the core of this question.

Since delete is basically the root of the currently accepted answer by Yochai Akoka, it's important to remember what delete does. It's irrelevant if not combined with the concepts of how GC works in the next two answers: if there's an existing reference to an object it's not cleaned up. The answers are more correct, but probably not as appreciated because they require more thought than just writing 'delete'. Yes, one possible solution may be to use delete, but it won't matter if there's another reference to the memory leak.

Another answer appropriately mentions circular references and the Chrome team documentation can provide much more clarity as well as the tools to verify the cause.

Since delete was mentioned here, it also may be useful to provide the resource Understanding Delete. Although it does not get into any of the actual solution which is really related to javascript's garbage collector.


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