What is the difference between == and === in JavaScript?  I have also seen != and !== operators.  Are there more such operators?
I'm using  to go through JavaScript, and it's returning many suggestions to replace == (two equals signs) with === (three equals signs) when doing things like comparing idSele_UNVEHtype.value.length == 0 inside of an if statement.  Is there a performance benefit to replacing == with ===?   Any performance improvement would be welcomed as many comparison operators exist.  If no type conversion takes place, would there be a performance gain over ==?
Crop jpeg into circular tikz node \documentclass[demo]{article} \usepackage{graphicx} \usepackage{tikz} \begin{document} \begin{tikzpicture} \node[circle,draw,inner sep=2cm]{\includegraphics{myimage.jpg}}; \end{tikzpicture} \end{document}   How do I modify the above code so that the included image is adapted to the circle shape and cropped of the exceeding parts?  I want to specify a shape (a circle) and then include an image respecting the given dimension and cropped. Preventing reverse search engines from finding the origin of your image? I am planning to make a game, where I give the user an anime related image and they have to guess where its from.  However, most of the images, specially from popular anime are easy to use on Google reverse search to find and pin point the anime.  I've tried to see if I could make so it would not recognize the image but unhappily my tricks were not good enough.  Original image:    Grey-scale with horizontal flip:    Watermarking:    Puzzling the image with grey-scale:    Grey-scale with horizontal and vertical flip worked for this image but doesn't always work:    Also the above mentioned methods are rather easy for people to guess the anime.  I would like to know if there any good trick, that I could use on my images to make so it would not work on reverse search engines and yet not be so overcomplicated that I can implement on my program.  For example grey-scale, cropping, flipping are rather easy things to achieve in C#. Best practices for making a WordPress site "movable"? I'm planning to buy a domain and install a WordPress site on it at a web-hosting company.  But first I'll need to iron-out some bugs...  I got a working LAMP-stack at my home-computer, so I'm thinking about first installing my site locally - off the Internet.  I'll be mostly tweaking and making "test-posts" to check that everything works, but I'll probably also make some posts I'd like to keep when I move the site and take it online.  When I'm done chasing bugs; I guess I'll just package the public_html|www directory-tree and upload it to the web-hosting company, and also export the database from my home-computer to the web-hosting.    What I'm wondering if there are some "best practices", some do-s and don't-s, some major pits to take note of?    For example, how can ensure the smooth transition of domain-name in posts and links as such, from localhost to whatever-i-end-up-buying.com (I know from previous attempt of running WordPress at my home computer, that this didn't always work quite well...). What does the above Error mean? What is an installation candidate?  I was trying to do  sudo apt-get install munin-memcached     and I get this message:  Reading package lists... Done Building dependency tree        Reading state information... Done Package munin-memcached is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package munin-memcached has no installation candidate   I googled for the problem and someone said to do a apt-get upgrade but it still did not solve my problem. What is a glue record? This is a  about DNS glue records.   What exactly (but briefly) is a DNS glue record?  Why are they needed and how do they work? I am trying to run Notepad as admin so I can edit my hosts file from the command line.  I have tried runas /user:(myusername)\administrator "notepad c:\windows\system32\drivers\etc\hosts" I then input my password and I get     RUNAS ERROR: Unable to run - notepad   c:\windows\system32\drivers\etc\hosts 1327: Account restrictions are   preventing this user from signing in. For example: blank pa sswords   aren't allowed, sign-in times are limited, or a policy restriction has   been enforc ed.   PS: I know if I give permission to my user account I can edit it without running as admin. But I'd like to know how to do this without having to change permissions on the hosts file. Finding maximal sublist of linearly independent vectors Breaking a hard-link in-place? I am keeping my dotfiles under version control and the script deploying them creates hard links. I also use etckeeper to put my /etc under version control. Recently I have gotten warnings like this:  warning: hard-linked files could cause problems with bzr   A simple copy (cp filename.ext filename.ext) will not work:  cp: `filename.ext' and `filename.ext' are the same file   Renaming/moving a file - except across volumes - also doesn't break the hard-link.  So my question is: is there a way to break a hard-link to a file without actually having to know where the other hard-link/s to that file is/are? Should 'Hi', 'thanks', taglines, and salutations be removed from posts? I edit a lot of posts every day. I often run across posts with 'Hi' and 'Thanks' on the top and the bottom of the post respectively. I also run across things like:     --User   Should these items be removed during the editing of the post by an editor? How do I instantiate a string array object into a Spring.Net container? Can you be tripped by an AoO while standing up? Pipe sound output to file? iPhone 4 water damage - how to recover data? What determines which pokemon you are allowed to place at a gym? So I defeated a Team Valor gym earlier today using my highest cp Pidgeot. It turned grey, so I went to claim it with that Pidgeot, except it wouldn't let me. What determines which pokemon you are allowed to place at a gym? Is it just those who have participated in a battle can't? Is there a time period for it? What about training at a friendly gym? Does this impact anything? This is something that I always find a bit hard to explain to others:  Why do XML namespaces exist?  When should we use them and when should we not? What are the common pitfalls when working with namespaces in XML?   Also, how do they relate to XML schemas? Should XSD schemas always be associated with a namespace? Is it possible to have the Corruption and the Crimson Biomes in the same world? I was reading on the wiki how there is a chance that the Corruption will be replaced with the Crimson.  I am wondering if when you get a world where you have the Crimson is it possible to also have the Corruption if you bring over corruption seeds from another world and use them. Or would these seeds just get you more of the Crimson? Windows 7 time issues Our company has multiple domains set up with one website hosted on each of the domains. At this time, each domain has its own authentication which is done via cookies.   When someone logged on to one domain needs to access anything from the other, the user needs to log in again using different credentials on the other website, located on the other domain.   I was thinking of moving towards single sign on (SSO), so that this hassle can be eliminated. I would appreciate any ideas on how this could be achieved, as I do not have any experience in this regard.  Thanks.  Edit: The websites are mix of internet (external) and intranet (internal-used within the company) sites. What does the symbol $\subset\subset$ mean? In some texts (mainly complex analysis or harmonic analysis) I sometimes see the following double subset symbol $\subset\subset$ for inclusion relation of two regions, e.g., $\Omega$ and $\Omega'$ are two regions in $\mathbb{C}$ such that $\Omega \subset\subset \Omega'$. I never figured out what it means exactly; I always interpreted it as the closure $\overline{\Omega}$ is contained in $\Omega'$ (so that some nasty boundary effects can be avoided). Is that right? Or does $\subset\subset$ mean some other kind of inclusion? Thanks. How do I iterate over a range of numbers defined by variables in Bash?