These things are the same (*edit* semantically; performance is a little better with `.now()`):

    var t1 = Date.now();
    var t2 = new Date().getTime();

However, the time value from any already-created `Date` instance is frozen at the time of its construction (or at whatever time/date it&#39;s been set to). That is, if you do this:

    var now = new Date();

and then wait a while, a subsequent call to `now.getTime()` will tell the time at the point the variable was set.

They are effectively equivalent, but you should use `Date.now()`. It&#39;s clearer and about twice as fast.

Edit: Source: http://jsperf.com/date-now-vs-new-date

When you do `(new Date()).getTime()` you are creating a new Date object. If you do this repeatedly, it will be about 2x slower than Date.now()

The same principle should apply for `Array.prototype.slice.call(arguments, 0)` vs `[].slice.call(arguments, 0)`

Yes, that is correct; they are effectively equivalent when using the current time.

Sometimes it&#39;s preferable to keep some time tracking variable in a Date object format rather than as just a number of milliseconds, to have access to Date&#39;s methods without re-instantiating. In that case, Date.now() still wins over new Date() or the like, though only by about 20% on my Chrome and by a tiny amount on IE.

See my JSPERF on

    timeStamp2.setTime(Date.now()); // set to current;

vs.

    timeStamp1 = new Date(); // set to current;

[http://jsperf.com/new-date-vs-settime][1]


  [1]: http://jsperf.com/new-date-vs-settime

Is there a way to do method overloading in TypeScript language?

I want to achieve something like this:

    class TestClass {
    	someMethod(stringParameter: string): void {
    		alert(&quot;Variant #1: stringParameter = &quot; + stringParameter);
    	}
    	
    	someMethod(numberParameter: number, stringParameter: string): void {
    		alert(&quot;Variant #2: numberParameter = &quot; + numberParameter + &quot;, stringParameter = &quot; + stringParameter);
    	}
    }
    
    var testClass = new TestClass();
    testClass.someMethod(&quot;string for v#1&quot;);
    testClass.someMethod(12345, &quot;string for v#2&quot;);

Here is an example of what I don&#39;t want to do (I really hate that part of overloading hack in JS):

	class TestClass {
		private someMethod_Overload_string(stringParameter: string): void {
			// A lot of code could be here... I don&#39;t want to mix it with switch or if statement in general function
			alert(&quot;Variant #1: stringParameter = &quot; + stringParameter);
		}
		
		private someMethod_Overload_number_string(numberParameter: number, stringParameter: string): void {
			alert(&quot;Variant #2: numberParameter = &quot; + numberParameter + &quot;, stringParameter = &quot; + stringParameter);
		}
		
		private someMethod_Overload_string_number(stringParameter: string, numberParameter: number): void {
			alert(&quot;Variant #3: stringParameter = &quot; + stringParameter + &quot;, numberParameter = &quot; + numberParameter);
		}
		
		public someMethod(stringParameter: string): void;
		public someMethod(numberParameter: number, stringParameter: string): void;
		public someMethod(stringParameter: string, numberParameter: number): void;

		public someMethod(): void {
			switch (arguments.length) {
			case 1:
				if(typeof arguments[0] == &quot;string&quot;) {
					this.someMethod_Overload_string(arguments[0]);
					return;
				}
				return; // Unreachable area for this case, unnecessary return statement
			case 2:
				if ((typeof arguments[0] == &quot;number&quot;) &amp;&amp;
					(typeof arguments[1] == &quot;string&quot;)) {
					this.someMethod_Overload_number_string(arguments[0], arguments[1]);
				}
				else if ((typeof arguments[0] == &quot;string&quot;) &amp;&amp;
						 (typeof arguments[1] == &quot;number&quot;)) {
					this.someMethod_Overload_string_number(arguments[0], arguments[1]);
				}
				return; // Unreachable area for this case, unnecessary return statement
			}
		}
	}


	var testClass = new TestClass();
	testClass.someMethod(&quot;string for v#1&quot;);
	testClass.someMethod(12345, &quot;string for v#2&quot;);
	testClass.someMethod(&quot;string for v#3&quot;, 54321);

Is there a way to do method overloading in TypeScript?

Quite often it is the case that you&#39;re writing a project of some kind, and after a while it becomes clear that some component of the project is actually useful as a standalone component (a library, perhaps). If you&#39;ve had that idea from early on, then there&#39;s a fair chance that most of that code is in its own folder.

Is there a way to convert one of the sub directories in a Git project to a submodule?

Ideally this would happen such that all of the code in that directory is removed from the parent project, and the submodule project is added in its place, with all the appropriate history, and such that all the parent project commits point to the correct submodule commits.


Convert a Git folder to a submodule retrospectively?

    var timeInMs = Date.now();

per [MDN][1]

vs.

    var timeInMs = new Date(optional).getTime();

per [MDN][2].

Is there any difference between the two, besides the syntax and the ability to set the Date (to not the current) via optional in the second version?

Date.now() is faster - check out the [jsperf][3]


  [1]: https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Date/now
  [2]: https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Date/getTime
  [3]: http://jsperf.com/gettime-vs-now-0

Performance - Date.now() vs Date.getTime()

<pre><code class="hljs language-ini">var timeInMs = Date.now();
</code></pre>
per <a href="https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Date/now" target="_blank" rel="noopener noreferrer">MDN</a>
vs.
<pre><code class="hljs language-ini">var timeInMs = new Date(optional).getTime();
</code></pre>
per <a href="https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Date/getTime" target="_blank" rel="noopener noreferrer">MDN</a>.
Is there any difference between the two, besides the syntax and the ability to set the Date (to not the current) via optional in the second version?
Date.now() is faster - check out the <a href="http://jsperf.com/gettime-vs-now-0" target="_blank" rel="noopener noreferrer">jsperf</a>

I just came across a blog that mentions a `j` function in Rails.  They were using it to do ajax style page updates.

    $(&#39;#cart&#39;).html(&quot;&lt;%=j render @cart %&gt;&quot;);

I get they are using partials to render the `cart` partial, but whats the point of `j`? I&#39;ve found some articles that say it converts the string to something JavaScript will accept, but what does that mean?

What does the j function in Rails do?

**UPDATE:** [Colin][1]&#39;s suggestion of removing the line //= require_tree . has fixed the issue.

I have wasted over 2 days trying to follow every suggestion out there and fix my issue. I am trying to follow the http://ruby.railstutorial.org book on windows machine and cannot for the life of me get past the following nasty error.

    ExecJS::RuntimeError in Static_pages#home

    Showing C:/Users/.../bootcamp-sample-app/app/views/layouts/application.html.erb where line #6 raised:

    [&quot;ok&quot;,&quot;(function() {\n\n\n\n}).call(this);\n&quot;]
    (in C:/Users/.../bootcamp-sample-app/app/assets/javascripts/sessions.js.coffee)
    Extracted source (around line #6):

    3: &lt;head&gt;
    4:   &lt;title&gt;&lt;%= full_title(yield(:title)) %&gt;&lt;/title&gt;
    5:   &lt;%= stylesheet_link_tag    &quot;application&quot;, media: &quot;all&quot; %&gt;
    6:   &lt;%= javascript_include_tag &quot;application&quot; %&gt;
    7:   &lt;%= csrf_meta_tags %&gt;
    8:   &lt;%= render &#39;layouts/shim&#39; %&gt;
    9: &lt;/head&gt;
    Rails.root: C:/Users/.../bootcamp-sample-app

    Application Trace | Framework Trace | Full Trace
    app/views/layouts/application.html.erb:6:in `_app_views_layouts_application_html_erb___487732698_30422172&#39;
    Request


I have tried every suggestion including installing nodejs with the msi, using execjs 1.3.0 and other things which I can&#39;t even remember any more. Here is the **gem file** 

    source &#39;https://rubygems.org&#39;
    
    gem &#39;rails&#39;, &#39;3.2.8&#39;
    gem &#39;bootstrap-sass&#39;, &#39;2.0.0&#39;
    gem &#39;bcrypt-ruby&#39;, &#39;3.0.1&#39;
    gem &#39;faker&#39;, &#39;1.0.1&#39;
    gem &#39;will_paginate&#39;, &#39;3.0.3&#39;
    gem &#39;bootstrap-will_paginate&#39;, &#39;0.0.6&#39;
    
    group :development, :test do
      gem &#39;sqlite3&#39;, &#39;1.3.5&#39;
      gem &#39;rspec-rails&#39;, &#39;2.10.0&#39;
      gem &#39;guard-rspec&#39;, &#39;0.5.5&#39;
      gem &#39;guard-cucumber&#39;
    end
    
    group :development do
      gem &#39;annotate&#39;, &#39;2.5.0&#39;
    end
    
    
    # Gems used only for assets and not required
    # in production environments by default.
    group :assets do
      gem &#39;sass-rails&#39;
      gem &#39;coffee-rails&#39;
      gem &#39;coffee-script&#39;
      gem &#39;uglifier&#39;
    end
    
    gem &#39;jquery-rails&#39;, &#39;2.0.2&#39;
    
    gem &#39;execjs&#39;
    
    # Gems on Linus/Mac
    #gem &#39;therubyracer&#39;
    
    
    group :test do
      gem &#39;capybara&#39;, &#39;1.1.2&#39;
      gem &#39;guard-spork&#39;, &#39;0.3.2&#39;
      gem &#39;spork&#39;, &#39;0.9.0&#39;
      gem &#39;factory_girl_rails&#39;, &#39;1.4.0&#39;
      gem &#39;cucumber-rails&#39;, &#39;1.2.1&#39;, require: false
      gem &#39;database_cleaner&#39;, &#39;0.7.0&#39;
    
    
    # Test gems on Linux
    #  gem &#39;rb-inotify&#39;, &#39;0.8.8&#39;
    #  gem &#39;libnotify&#39;, &#39;0.5.9&#39;
    
    # Test gems on Macintosh OS X
    #  gem &#39;selenium-webdriver&#39;, &#39;~&gt; 2.22.0&#39;
    #  gem &#39;rb-fsevent&#39;, &#39;0.9.1&#39;, :require =&gt; false
    #  gem &#39;growl&#39;, &#39;1.0.3&#39;
    
    # Test gems on Windows
    # gem &#39;rb-fchange&#39;, &#39;0.0.5&#39;
    # gem &#39;rb-notifu&#39;, &#39;0.0.4&#39;
    # gem &#39;win32console&#39;, &#39;1.3.0&#39;
    end
    
    group :production do
    #  gem &#39;therubyracer&#39;
      gem &#39;pg&#39;, &#39;0.12.2&#39;
    end
    
    # To use ActiveModel has_secure_password
    # gem &#39;bcrypt-ruby&#39;, &#39;~&gt; 3.0.0&#39;
    
    # To use Jbuilder templates for JSON
    # gem &#39;jbuilder&#39;
    
    # Use unicorn as the app server
    # gem &#39;unicorn&#39;
    
    # Deploy with Capistrano
    # gem &#39;capistrano&#39;
    
    # To use debugger
    #gem &#39;debugger&#39;&#39;

and here is the **sessions.js.coffee**

    # Place all the behaviors and hooks related to the matching controller here.
    # All this logic will automatically be available in application.js.
    # You can use CoffeeScript in this file: http://jashkenas.github.com/coffee-script/

**application.js**

    // This is a manifest file that&#39;ll be compiled into application.js, which will include all the files
    // listed below.
    //
    // Any JavaScript/Coffee file within this directory, lib/assets/javascripts, vendor/assets/javascripts,
    // or vendor/assets/javascripts of plugins, if any, can be referenced here using a relative path.
    //
    // It&#39;s not advisable to add code directly here, but if you do, it&#39;ll appear at the bottom of the
    // the compiled file.
    //
    // WARNING: THE FIRST BLANK LINE MARKS THE END OF WHAT&#39;S TO BE PROCESSED, ANY BLANK LINE SHOULD
    // GO AFTER THE REQUIRES BELOW.
    //
    //= require jquery
    //= require jquery_ujs
    //= require_tree .
    //= require bootstrap

**application.html.erb**

    &lt;!DOCTYPE html&gt;
     &lt;html&gt;
     &lt;head&gt;
       &lt;title&gt;&lt;%= full_title(yield(:title)) %&gt;&lt;/title&gt;
       &lt;%= stylesheet_link_tag    &quot;application&quot;, media: &quot;all&quot; %&gt;
       &lt;%= javascript_include_tag &quot;application&quot; %&gt;
       &lt;%= csrf_meta_tags %&gt;
       &lt;%= render &#39;layouts/shim&#39; %&gt;
     &lt;/head&gt;
     &lt;body&gt;
     &lt;%= render &#39;layouts/header&#39; %&gt;
     &lt;div class=&quot;container&quot;&gt;
       &lt;%= yield %&gt;
       &lt;%= render &#39;layouts/footer&#39; %&gt;
     &lt;/div&gt;
     &lt;/body&gt;
     &lt;/html&gt;

Here is **console content**

    Processing by StaticPagesController#home as HTML
      Rendered static_pages/home.html.erb within layouts/application (45.0ms)
    Completed 500 Internal Server Error in 1136ms

    ActionView::Template::Error ([&quot;ok&quot;,&quot;(function() {\n\n\n\n}).call(this);\n&quot;]
      (in C:/Users/.../bootcamp-sample-app/app/assets/javascripts/sessions.js.coffee)):
        3: &lt;head&gt;
        4:   &lt;title&gt;&lt;%= full_title(yield(:title)) %&gt;&lt;/title&gt;
        5:   &lt;%= stylesheet_link_tag    &quot;application&quot;, media: &quot;all&quot; %&gt;
        6:   &lt;%= javascript_include_tag &quot;application&quot; %&gt;
        7:   &lt;%= csrf_meta_tags %&gt;
        8:   &lt;%= render &#39;layouts/shim&#39; %&gt;
        9: &lt;/head&gt;
      app/views/layouts/application.html.erb:6:in `_app_views_layouts_application_html_erb___487732698_30422172&#39;


      Rendered C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/actionpack-3.2.8/lib/action_dispatch/middleware/templates/rescues/_trace.erb (2.0ms)
      Rendered C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/actionpack-3.2.8/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (1.0ms)
      Rendered C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/actionpack-3.2.8/lib/action_dispatch/middleware/templates/rescues/template_error.erb within rescues/layout (34.0ms)


I have installed Devkit and have tried various gems but please suggest changes which can help me develop on windows. I used rubyinstaller for everything.

What am I missing?


  [1]: https://stackoverflow.com/users/1017768/colin-r

ExecJS::RuntimeError on Windows trying to follow rubytutorial

Is there a js listener for when a user scrolls in a certain textbox that can be used? Kinda like onclick except for scrolling. I saw https://stackoverflow.com/questions/5669207/html5-event-listener-for-number-input-scroll-chrome-only but that seems to be for chrome only. I&#39;m looking for something cross-browser.

Scroll event listener javascript

I&#39;m using express + node.js and I have a req object, the request in the browser is /account but when I log req.path I get &#39;/&#39; --- not &#39;/account&#39;.

      //auth required or redirect
      app.use(&#39;/account&#39;, function(req, res, next) {
        console.log(req.path);
        if ( !req.session.user ) {
          res.redirect(&#39;/login?ref=&#39;+req.path);
        } else {
          next();
        }
      });


req.path is / when it should be /account ??

how to get request path with express req object

If a DOM Element is removed, are its listeners removed from memory too?

Content Type	Original Author	Original Content on Stackoverflow
Question	user656925	View Question on Stackoverflow
Solution 1 - Javascript	Pointy	View Answer on Stackoverflow
Solution 2 - Javascript	jonvuri	View Answer on Stackoverflow
Solution 3 - Javascript	Gregory Magarshak	View Answer on Stackoverflow
Solution 4 - Javascript	Brett Zamir	View Answer on Stackoverflow
Solution 5 - Javascript	SashaK	View Answer on Stackoverflow

Performance - Date.now() vs Date.getTime()

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

Solution 3 - Javascript

Solution 4 - Javascript

Solution 5 - Javascript

Convert a Git folder to a submodule retrospectively?

Is there a way to do method overloading in TypeScript?

Attributions