How do you check if a selector matches something in jQuery? In Mootools, I'd just run if ($('target')) { ... }.  Does if ($('#target')) { ... } in jQuery work the same way?
Is there an "exists" function for jQuery? How can I check the existence of an element in jQuery?  The current code that I have is this:  if ($(selector).length &gt; 0) {     // Do something }   Is there a more elegant way to approach this? Perhaps a plugin or a function?
Automorphism group of the quaternion group Let $Q_8$ be the quaternion group. How do we determine the automorphism group $Aut(Q_8)$ of $Q_8$ algebraically? I searched for this problem on internet. I found some geometric proofs that $Aut(Q_8)$ is isomorphic to the rotation group of a cube, hence it is isomorphic to the symmetric group $S_4$. I would like to know an algebraic proof that $Aut(Q_8)$ is isomorphic to $S_4$. AMT stock option scenario How to get Beamer Math to look like Article Math Split seeds.rb into multiple sections? Found this when subscribing to jQuery tag. "unsubscribe | rss" is not shown correctly. Prove that Gauss map on M is surjective Is it okay to keep flour in the freezer? Years ago I noticed I was getting little bugs in the flour that I kept in the pantry.  To prevent this, I started keeping my flour in the freezer.  I don't do a lot of baking, but I was wondering what effects this might have on anything I do bake.  Do baked goods turn out any differently when flour is kept in the freezer vs flour kept at room temperature?  Also, if it's okay to freeze flour, how long will it last this way? Are there good reasons why it's a better practice to have only one return statement in a function?   Or is it okay to return from a function as soon as it is logically correct to do so, meaning there may be many return statements in the function? CPU cooler does not fit, will it cool worse if I cut tips of heatpipes off? Case: zalman z9 neo  Cooler: deepcool gammaxx 400  According to specs it should fit, but it does not, probably because my motherboard is mini-itx and cooler located a bit to the left  I'm thinking that cutting off those tips of heatpipes on the left would solve that; if I do that, will cooler work worse, like heatpipes would transfer heat not as good or something? Many sysv init scripts used a corresponding file in /etc/default to allow the administrator to configure it. Upstart jobs can be modified using .override files. How do I override or configure systemd units, now that systemd is the default in Ubuntu? Conjugating verbs for nouns referring to groups of people Possible Duplicate:          Frequently when reading tech articles, I see sentences like "Microsoft have released ..." or "Apple have announced ...". This seems wrong to me because the nouns are singular; Microsoft and Apple are individual companies, even though they refer to groups of people. I have not seen this usage outside of tech journalism, but it's pervasive enough that it makes me wonder: is this actually the correct usage?  As a follow-up question, is it correct to use a plural pronoun for a singular antecedent like this? For example, "Apple has announced they are changing their name to Orange" or "Apple has announced it is changing its name to Orange". The second form seems technically correct but sounds awkward. What will be the one's digit of the remainder in: $\left|5555^{2222} + 2222^{5555}\right|\div 7=?$ Using Blender Game Engine for VR 360 tour on Mobile, is it doable? I'm sorry if my question sounds clumsy, I'm not a seasoned BGE user.  I'd like to make a virtual tour for Gear VR and/or Google Cardboard in the BGE that works on Mobile.  Is this doable in a user friendly way using the BGE? Can I export to Mobile (android, IOS, Windows Phone)? I know this is possible using Unity, but I find Unity difficult to use. I've tried UE4, but the process is a big mess, it requires a buggy multi-level hack that only results in wasting my time. An idiom for deriving pleasure from another's suffering I believe it is what the Germans call "". English itself has no such equivalent word. (Although it has been adopted as a .)  Does an idiom exist that describes it? File.Copy is giving exception I just realized I can't unrar .rar files on my Ubuntu machine!  What's the easiest way to accomplish this fundamental task? If possible I'd love something like 7Zip that I can just right Click, and extract and have the program worry about how to do it regardless if it's a .zip, a .rar or a .foo compressed file. Proof verification: Set of partial limits of a sequence is closed Using the same RSA keypair to sign and encrypt The RSA signature operation is basically the same as encrypting with the private key.  In particular, both operations use the same kind of keys.  Is it safe to use the same RSA keypair both for encryption / decryption and for signing / verification? What is the difference between a population and a sample? What is the difference between a population and a sample? What common variables and statistics are used for each one, and how do those relate to each other? Python BeautifulSoup findAll by "class" attribute