blocks|key|1624613|text|我不确定，但他们可能会使用它，所以网站上的所有内容都会先加载并显示给用户，然后才会加载并显示广告。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1624614|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

I don't know for certain, but they might use it so all the content on the website is loaded and shown to the user first, then the ads are loaded and shown.

blocks|key|1624681|text|要将其与正则表达式相匹配，并将其删除很容易：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1624682|<script+type='text/javascript'+src='http://addomain/someadd.js'></script>|code-block|syntax|javascript|1624683|但另一个更复杂，可以用不同的格式编写。|1624684|我想这就是原因。|1624685|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

To match this with regex and to remove is easy : 

<pre><code>&lt;script type='text/javascript' src='http://addomain/someadd.js'&gt;&lt;/script&gt;
</code></pre>

but the other is more complex and can be written in different formats. 

I think this is the reason.

blocks|key|1410023|text|如果禁用了活动脚本，此方法可避免加载外部脚本。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1410024|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

This method avoids loading the external script if active scripting is disabled.

blocks|key|1624797|text|我在一家网络广告公司工作，据我所知，某些浏览器(不知道是哪种浏览器)允许你将脚本标签放入页面，但不允许你自动执行它们的内容。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1624798|因此，要实现这一点，您需要将脚本标记拆分，以便浏览器不会将其视为脚本标记，而是将其视为任何旧的HTML数据。然后，当DOM被串行处理时，在写出脚本标记之后，它计算的下一件事是...嘿，你刚写的脚本标签。|1624799|在这一点上，脚本标记被计算并执行。|1624800|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|I|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|G|$]]

I work with a web advertising company, and from what I've heard, certain browsers (don't know off hand which ones) will allow you to drop script tags into the page, but won't allow you to automatically execute their contents.

So, to pull this off, you need to break the script tag into pieces so the browser doesn't treat it as a script tag, but rather as any old HTML Data. Then, as the DOM is processed serially, the next thing it evaluates, after writing out the script tag is... hey, that script tag you just wrote out.

At this point the script tag is evaluated and executed.

blocks|key|1410123|text|通常，这些document.write注入脚本会附加动态字符串，以脱离缓存，或者将客户端的一些信息发送到广告服务器。我怀疑您的示例是这样开始的|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1410124|document.write("<script+type='text/javascript'+src='http://addomain/someadd.js?"%2Bextrastuff%2B"'><\/sc"+%2B+"ript>");|code-block|syntax|javascript|1410125|但随着时间的推移被调整了，或者被一些不理解额外内容的人复制和修改。但正如你所写的，没有区别:你在问题中引用的两种方式在功能上是相同的。|1410126|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Often these document.write injected scripts have dynamic strings attached to them to bust out of caching, or to send some info about the client to the ad server. I suspect your example started out as something like this 

<pre><code>document.write("&lt;script type='text/javascript' src='http://addomain/someadd.js?"+extrastuff+"'&gt;&lt;\/sc" + "ript&gt;");
</code></pre>

but got tweaked over time, or was copied and modified by someone who didn't understand the extrastuff bit. But as you've written it there is no difference: the two ways you cite in your question are functionally the same.

blocks|key|1410154|text|我的天，这不仅毫无意义，甚至是不正确的。尖括号没有被转义，这将使文档在技术上无效的HTML+(即使它可以在所有主要的浏览器中工作，因为他们试图从程序员的错误中恢复)。如果有人将XHMTL页面作为application/xml%2Bxhtml提供给他的站点，document.write()根本就不能工作。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1410155|entityMap^0|2P|L|3I|G|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

IMHO, that's not only pointless, but even incorrect. Angle brackets are not escaped, which'll render document technically invalid HTML (even though it'll work in all major browsers, because they try to recover from coders' errors). And in case one's serving his site with XHMTL pages as <code>application/xml+xhtml</code>, <code>document.write()</code> just won't work at all.

blocks|key|1624914|text|传统的脚本标记会在页面加载和执行时阻塞页面。使用document.write加载的脚本将异步工作。这就是为什么你会在广告或分析中看到这一点，因为这样的脚本不会直接影响页面内容。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1624915|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

A traditional script tag will block the page while it is loading and executing. A script loaded with document.write will work asynchronously. That's why you see this on ads or analytics, as such scripts don't influence the page content directly.

blocks|key|1624963|text|一种方法来减少他们的添加被阻止的可能性。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1624964|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

A way to make it somewhat less likely their add is blocked.

blocks|key|1625010|text|write()方法主要用于测试:如果在HTML文档完全加载之后使用它，它将删除所有现有的HTML|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1625011|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

The write() method is mostly used for testing: If it is used after an HTML document is fully loaded, it will delete all existing HTML

I was wondering why ad's still use the document.write approach to inserting the add into the page 

<pre><code>&lt;script language="javascript" type="text/javascript"&gt;
 document.write("&lt;script type='text/javascript' src='http://addomain/someadd.js'&gt;&lt;\/sc" + "ript&gt;");
&lt;/script&gt;
</code></pre>

Why is it that I can't just put 

<pre><code>&lt;script type='text/javascript' src='http://addomain/someadd.js'&gt;&lt;/script&gt;
</code></pre>

In place of the ad?

Why use document.write?

服务器

我想知道为什么广告仍然使用document.write方法将add插入到页面中<script language="javascript" type="text/javascript"> document.write("<script type='text/javascript' src='http://addom...

问为什么使用document.write？
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