Checkout http://ejohn.org/blog/deep-tracing-of-internet-explorer/ the dynaTrace tool shown here is fantastic and works with IE7.

The Internet Explorer 8 beta (2) has a builtin Javascript profiler (in the developer toolbar).  It&#39;s worth playing with at least...

[JavaScript Profiler][1] is a decent tool.


  [1]: http://www.whitefrost.com/documents/html/technical/dhtml/jsprof.html

YUI also provides a [profiler](http://developer.yahoo.com/yui/profiler/).

[js-profiler][1] also provide a profiler that is working in any browser and does not depend on any framework.


  [1]: http://github.com/jeremi/js-profiler

I don&#39;t think [debugbar][1] has a profiler.. but it does have a debugger and a console... so you can fake it...


  [1]: http://www.debugbar.com/

We use Firebugs console.log, console.time and console.timeEnd (I think) a lot.

Firebug also has a built in profiler.

The [DOI][1] system places basically no useful limitations on what constitutes [a reasonable identifier][2]. However, being able to pull DOIs out of PDFs, web pages, etc. is quite useful for citation information, etc.

Is there a reliable way to identify a DOI in a block of text without assuming the &#39;doi:&#39; prefix? (any language acceptable, regexes preferred, and avoiding false positives a must)


  [1]: http://doi.org/
  [2]: http://doi.org/handbook_2000/enumeration.html#2.2

Finding a DOI in a document or page

In C#, if I have an inherited class with a default constructor, do I have to explicitly call the base class&#39; constructor or will it be implicitly called?

    class BaseClass
    {
        public BaseClass()
        {
            // ... some code
        }
    }
    class MyClass : BaseClass
    {
        public MyClass() // Do I need to put &quot;: base()&quot; here or is it implied?
        {
            // ... some code
        }
    }


In C#, do you need to call the base constructor?

Does anyone know a tool for Profiling JavaScript in IE?

List available:

  - [IE8][1] (Internet Explorer 8 only)
  - [JavaScript Profiler][2]
  - [YUI!][3]


  [1]: http://blogs.msdn.com/ie/archive/2008/09/11/introducing-the-ie8-developer-tools-jscript-profiler.aspx
  [2]: http://www.whitefrost.com/documents/html/technical/dhtml/jsprof.html
  [3]: http://developer.yahoo.com/yui/profiler/

JavaScript Profiler in IE

<p>Does anyone know a tool for Profiling JavaScript in IE?</p>
<p>List available:</p>
<ul>
<li><a href="http://blogs.msdn.com/ie/archive/2008/09/11/introducing-the-ie8-developer-tools-jscript-profiler.aspx" target="_blank" rel="noopener noreferrer">IE8</a> (Internet Explorer 8 only)</li>
<li><a href="http://www.whitefrost.com/documents/html/technical/dhtml/jsprof.html" target="_blank" rel="noopener noreferrer">JavaScript Profiler</a></li>
<li><a href="http://developer.yahoo.com/yui/profiler/" target="_blank" rel="noopener noreferrer">YUI!</a></li>
</ul>


How can you reliably and dynamically load a JavaScript file?  This will can be used to implement a module or component that when &#39;initialized&#39; the component will dynamically load all needed JavaScript library scripts on demand.

The client that uses the component isn&#39;t required to load all the library script files (and manually insert `&lt;script&gt;` tags into their web page) that implement this component - just the &#39;main&#39; component script file.

**How do mainstream JavaScript libraries accomplish this (Prototype, jQuery, etc)?**  Do these tools merge multiple JavaScript files into a single redistributable &#39;build&#39; version of a script file?  Or do they do any dynamic loading of ancillary &#39;library&#39; scripts?

An addition to this question: **is there a way to handle the event after a dynamically included JavaScript file is loaded?**  Prototype has `document.observe` for document-wide events. Example:

    document.observe(&quot;dom:loaded&quot;, function() {
      // initially hide all containers for tab content
      $$(&#39;div.tabcontent&#39;).invoke(&#39;hide&#39;);
    });

**What are the available events for a script element?**

Dynamically load a JavaScript file

I&#39;m looking for the best JavaScript editor available as an Eclipse plugin. I&#39;ve been using Spket which is good. But, is there more better one?

JavaScript editor within Eclipse

Does anyone know of an easy way to escape HTML from strings in [jQuery][1]?  I need to be able to pass an arbitrary string and have it properly escaped for display in an HTML page (preventing JavaScript/HTML injection attacks).  I&#39;m sure it&#39;s possible to extend jQuery to do this, but I don&#39;t know enough about the framework at the moment to accomplish this.


  [1]: http://jquery.com/

Escaping HTML strings with jQuery

Is there any JavaScript method similar to the jQuery `delay()` or `wait()` (to delay the execution of a script for a specific amount of time)?

Execute script after specific delay using JavaScript

What JavaScript keywords (function names, variables, etc) are reserved?

Reserved keywords in JavaScript

Before you answer this I have never developed anything popular enough to attain high server loads. Treat me as (sigh) an alien that has just landed on the planet, albeit one that knows PHP and a few optimisation techniques.

----------

I&#39;m developing a tool in **PHP** that could attain quite a lot of users, if it works out right. However while I&#39;m fully capable of developing the program I&#39;m pretty much clueless when it comes to making something that can deal with huge traffic. So here&#39;s a few questions on it (feel free to turn this question into a resource thread as well).

## Databases ##

At the moment I plan to use the MySQLi features in PHP5. However how should I setup the databases in relation to users and content? Do I actually *need* multiple databases? At the moment everything&#39;s jumbled into one database - although I&#39;ve been considering spreading user data to one, actual content to another and finally core site content (template masters etc.) to another. My reasoning behind this is that sending queries to different databases will ease up the load on them as one database = 3 load sources. Also would this still be effective if they were all on the same server?

## Caching ##

I have a template system that is used to build the pages and swap out variables. Master templates are stored in the database and each time a template is called it&#39;s cached copy (a html document) is called. At the moment I have two types of variable in these templates - a static var and a dynamic var. Static vars are usually things like page names, the name of the site - things that don&#39;t change often; dynamic vars are things that change on each page load.

My question on this:

Say I have comments on different articles. Which is a better solution: store the simple comment template and render comments (from a DB call) each time the page is loaded or store a cached copy of the comments page as a html page - each time a comment is added/edited/deleted the page is recached.

## Finally ##

Does anyone have any tips/pointers for running a high load site on PHP. I&#39;m pretty sure it&#39;s a workable language to use - Facebook and Yahoo! give it great precedence - but are there any experiences I should watch out for?

Tactics for using PHP in a high-load site

Is there a performance difference between `i++` and `++i` if the resulting value is not used?

Is there a performance difference between i++ and ++i in C?

We have the question [is there a performance difference between `i++` and `++i` **in C**?][1]

What&#39;s the answer for C++?

[1]: /q/24886

Is there a performance difference between i++ and ++i in C++?

I constantly hear how bad reflection is to use. While I generally avoid reflection and rarely find situations where it is impossible to solve my problem without it, I was wondering...   

For those who have used reflection in applications, have you measured performance hits and, is it really so bad?

How costly is .NET reflection?

So far, I&#39;ve only used Rational Quantify. I&#39;ve heard great things about Intel&#39;s VTune, but have never tried it!

Edit: I&#39;m mostly looking for software that will instrument the code, as I guess that&#39;s about the only way to get very fine results.

---

### See also:
[What are some good profilers for native C++ on Windows?][1]


  [1]: https://stackoverflow.com/questions/153559/what-are-some-good-profilers-for-native-c-on-windows

What&#39;s your favorite profiling tool (for C++)

What is the reason browsers do not correctly recognize:

    &lt;script src=&quot;foobar.js&quot; /&gt; &lt;!-- self-closing script element --&gt;

Only this is recognized:

    &lt;script src=&quot;foobar.js&quot;&gt;&lt;/script&gt;

Does this break the concept of XHTML support?

Note: This statement is correct at least for all IE (6-8 beta 2).

Why don&#39;t self-closing script elements work?

In IE, the dropdown-list takes the same width as the dropbox (I hope I am making sense) whereas in Firefox the dropdown-list&#39;s width varies according to the content. 

This basically means that I have to make sure that the dropbox is wide enough to display the longest selection possible. This makes my page look very ugly :(

Is there any workaround for this problem? 
How can I use CSS to set different widths for dropbox and the dropdownlist?


Dropdownlist width in IE

When I debug in Visual Studio, Firefox opens and that is annoying because of the hookups that Internet Explorer and Visual Studio have, such as when you close the Internet Explorer browser that starting debug opened, Visual Studio stops debugging.  How can I get Visual Studio to open Internet Explorer instead without having to set Internet Explorer as my default browser?


Visual Studio opens the default browser instead of Internet Explorer

I thought I&#39;d found the solution a while ago (see my [blog][1]):

&gt; If you ever get the JavaScript (or should that be JScript) error &quot;Can&#39;t execute code from a freed script&quot; - try moving any meta tags in the head so that they&#39;re before your script tags. 

...but based on one of the most recent blog comments, the fix I suggested may not work for everyone. I thought this would be a good one to open up to the StackOverflow community....

What causes the error &quot;Can&#39;t execute code from a freed script&quot; and what are the solutions/workarounds?

  [1]: https://tjrobinson.net/programming/technology/2006/09/03/cant-execute-code-from-a-freed-script.html

What causes the error &quot;Can&#39;t execute code from a freed script&quot;

Ran into this problem today, posting in case someone else has the same issue.

    var execBtn = document.createElement(&#39;input&#39;);
    execBtn.setAttribute(&quot;type&quot;, &quot;button&quot;);
    execBtn.setAttribute(&quot;id&quot;, &quot;execBtn&quot;);
    execBtn.setAttribute(&quot;value&quot;, &quot;Execute&quot;);
    execBtn.setAttribute(&quot;onclick&quot;, &quot;runCommand();&quot;);

Turns out to get IE to run an onclick on a dynamically generated element, we can&#39;t use setAttribute. Instead, we need to set the onclick property on the object with an anonymous function wrapping the code we want to run.

    execBtn.onclick = function() { runCommand() };

**BAD IDEAS:**

You can do 

    execBtn.setAttribute(&quot;onclick&quot;, function() { runCommand() });

but it will break in IE in non-standards mode according to @scunliffe.

You can&#39;t do this at all 

    execBtn.setAttribute(&quot;onclick&quot;, runCommand() ); 

because it executes immediately, and sets the result of runCommand() to be the onClick attribute value, nor can you do

    execBtn.setAttribute(&quot;onclick&quot;, runCommand);

Why does an onclick property set with setAttribute fail to work in IE?

What&#39;s the easiest way to profile a PHP script?

I&#39;d love tacking something on that shows me a dump of all function calls and how long they took but I&#39;m also OK with putting something around specific functions.

I tried experimenting with the [microtime][1] function:

    $then = microtime();
    myFunc();
    $now = microtime();

    echo sprintf(&quot;Elapsed:  %f&quot;, $now-$then);

but that sometimes gives me negative results.  Plus it&#39;s a lot of trouble to sprinkle that all over my code.

[1]: http://php.net/microtime

Simplest way to profile a PHP script

We are using [JetBrains][1]&#39; [dotTrace][2]. What other profiling tools can be recommended that are better for profiling C# [Windows Forms][3] applications?

  [1]: http://en.wikipedia.org/wiki/JetBrains
  [2]: http://en.wikipedia.org/wiki/DotTrace
  [3]: http://en.wikipedia.org/wiki/Windows_Forms


Best .NET memory and performance profiler?

I want to know the memory usage of my Python application and specifically want to know what code blocks/portions or objects are consuming most memory.
Google search shows a commercial one is [Python Memory Validator][1] (Windows only).

And open source ones are [PySizer][2] and [Heapy][3].

I haven&#39;t tried anyone, so I wanted to know which one is the best considering:

1. Gives most details.

2. I have to do least or no changes to my code.


  [1]: http://www.softwareverify.com/python/memory/index.html
  [2]: http://pysizer.8325.org/
  [3]: http://guppy-pe.sourceforge.net/#Heapy

Which Python memory profiler is recommended?

Is there a tool/plugin/function for Firefox that&#39;ll dump out a memory usage of Javascript objects that you create in a page/script? I know about Firebug&#39;s profiler but I&#39;d like something more than just times. Something akin to what Yourkit has for Java profiling of memory usage.

Reason is that a co-worker is using id&#39;s for &quot;keys&quot; in an array and is creating 1000&#39;s of empty slots when he does this. He&#39;s of the opinion that this is harmless whereas my opinion differs. I&#39;d like to offer some proof to prove whether I&#39;m right or not.

Content Type	Original Author	Original Content on Stackoverflow
Question	Daniel Silveira	View Question on Stackoverflow
Solution 1 - Javascript	user327872	View Answer on Stackoverflow
Solution 2 - Javascript	Andrew	View Answer on Stackoverflow
Solution 3 - Javascript	Greg Hurlman	View Answer on Stackoverflow
Solution 4 - Javascript	Walter Rumsby	View Answer on Stackoverflow
Solution 5 - Javascript	user257474	View Answer on Stackoverflow
Solution 6 - Javascript	danb	View Answer on Stackoverflow
Solution 7 - Javascript	ScottKoon	View Answer on Stackoverflow

JavaScript Profiler in IE

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

Solution 3 - Javascript

Solution 4 - Javascript

Solution 5 - Javascript

Solution 6 - Javascript

Solution 7 - Javascript

In C#, do you need to call the base constructor?

Finding a DOI in a document or page

Attributions