If I have a class with constants for example AppConstants and use  public static final variable from there like AppConstants.MY_STRING it would recreate this class all the time or it creates it during runtime because the fields in the class is static? So is it better to define file in constants or "at the place"?
To be specific, I was trying this code:  package hello;  public class Hello {      Clock clock = new Clock();      public static void main(String args[]) {         clock.sayTime();     } }   But it gave the error      Cannot access non-static field in static method main   So I changed the declaration of clock to this:  static Clock clock = new Clock();   And it worked. What does it mean to put that keyword before the declaration? What exactly will it do and/or restrict in terms of what can be done to that object?
Prove a differentiable function between banach spaces is continuous Feed can show entries for deleted posts, which viewing them fails I was looking for some shell commands, and I took a look in "users" command.  I was hoping to get only 1 name, but I got 2:  nori@nori-hidamari:~$ users nori nori   And when I run the command "who"  nori@nori-hidamari:~$ who nori     :0           2015-04-09 09:31 (:0) nori     pts/0        2015-04-09 09:48 (:0)   Is this behaviour normal? Or it's bad?  Thank you guys for helping me. What I want is to create a bootable pen drive that shows GRUB menu and I can select any of the several bootable systems from there to install/run. I have several ISO images that I want to install in the USB like Ubuntu, Fedora, System Rescue CD, Windows XP and Windows 7 (The windows versions are optional, mostly am looking for a multi installer for Linux distros, specially Ubuntu version)  The default Startup Disk Creator only works with Linux Images and only 1 at a time (At least for the mean time. If it allows more systems and multiple ISOs it would be awesome)  What method exists that I can use step by step to create a bootable USB Drive with multiple images than can be booted from the USB and selected from GRUB. It must support Windows Images and Linux Images.  Alternatively, is there also a way to have multiple versions of the Ubuntu installation ISO on same USB Drive, such as, when booting from it, I get to choose what Ubuntu version and architecture to install, for example:     BOOT MENU   Ubuntu 12.04 32 Bit   Ubuntu 12.04 64 Bit   Ubuntu 12.10 32 Bit   Ubuntu 12.10 64 Bit   UPDATE: Wanted to add that the English version for the post mentioned by daithib8 is here: Customizing tray/taskbar date display in Ubuntu with GNOME 3 If $X$ follows a Binomial distribution with parameters $n$ and $p$, what can we say on the distribution of $n\choose x$ and $x\choose n$ ? ($x$ is realization of $X$). Is there any way to keep a command from being added to your history? I have a command that I want to keep out of my history file, and I really don't care to have it there when I search the history stored in memory, though that's less of a concern. Is there any way to prevent this, or do I just have to go back and edit my history file.  update: I didn't realize this might be shell-specific. My shell is zsh. You're welcome to answer for other shells so people know how to do this in their shell. Why was the DeLorean in Back To The Future not always covered in ice after time travel, and why didn't it fly in 1885? In Python, you can do this:  import webbrowser webbrowser.open_new("http://example.com/")   It will open the passed in url in the default browser  Is there a ruby equivalent? How can I vertically align entries in my acronyms' list? I use the Glossaries package to generate it. Here is MWE:  % !TeX program = xelatex % !TeX encoding = utf-8 % !TeX spellcheck = ru_RU  \documentclass[12pt, a4paper]{article}  \usepackage{polyglossia} \setdefaultlanguage{russian} \setmainfont[Ligatures=TeX]{Times New Roman}  \usepackage[xindy={glsnumbers=false}, nonumberlist, nopostdot, nogroupskip]{glossaries} %\setglossarystyle{super} % uncomment for style "super" \makeglossaries  \begin{document}  \newacronym{bam}{ДАП}{Двунаправленная Ассоциативная Память} \newacronym{ai}{ИИ}{Искусственный Интеллект} \newacronym{am}{АП}{Ассоциативная Память} \newacronym{ann}{ИНС}{Искусственная Нейронная Сеть} \newacronym{an}{ИН}{Искусственный Нейрон} \newacronym{it}{ИТ}{Информационные Технологии} \glsaddall  \printglossaries  \end{document}   With the default style I have the following:  As you can see, the long names are not vertically aligned. What I want can be achieved with the    \setglossarystyle{super}   But it this case, short names lose the BOLDness, some small horizontal indent appears and the spacing between lines becomes smaller:  where RED is some extra indent, which I don't need. Thank you for your answers! $15x\equiv 20 \pmod{88}$ Euclid's algorithm Use Euclid's algorithm to find a multiplicative inverse of 15 mod 88, hence solve the linear congruence $15x\equiv 20 \pmod{88}$  So far I have:   $88=5\cdot15+13$  $15=1\cdot13+2$  Backwards substitution gives  $15v+18w=1$   $1=15-1\cdot13$   $=15-1(88-5\cdot15)$   $=15\cdot15-1\cdot88$   now very stuck what to do from here:( jQuery/JavaScript to replace broken images I have a web page that includes a bunch of images. Sometimes the image isn't available, so a broken image is displayed in the client's browser.  How do I use jQuery to get the set of images, filter it to broken images then replace the src?    --I thought it would be easier to do this with jQuery, but it turned out much easier to just use a pure JavaScript solution, that is, the one provided by Prestaul. Does a word rhyme with itself? If two limits don't exist, are we sure the limit of sum doesn't exist? This is a true/false question.     If the limits $$\lim_ {x\to a}\ f(x)\quad \text{ and }\quad  \lim_ {x\to a}\ g(x)$$ don't exist, limits $$\lim_ {x\to a}\ (f(x)+g(x))\quad \text{ and }\quad \lim_ {x\to a}\ (f(x)g(x))$$ don't exist also.   My idea is, that, because $$\lim_ {x\to a}\ (f(x)+g(x))=\lim_ {x\to a}\ f(x)+\lim_ {x\to a} g(x)$$ then the limits doesn't exist, correct? Can polymorphing monsters spam their ability to effectively give themselves a massive health pool? Some creatures have an ability that lets them polymorph, such as the Couatl's Change Shape action. I am wondering if this ability could be used again whenever the form is dropped to give the creature a massive effective health pool.  For example, if the Couatl used their action to Change Shape and become a Veteran, then was hit for enough damage to kill the polymorphed form, could it then re-use the Change Shape ability to transform into a fully healed Veteran once more? I'd like to be able to search for questions by multiple tags; for example "questions tagged 'nhibernate' and 'web-services'".  I can get close by searching for "nhibernate web-services" but the results tend to be a few questions that relate to both terms--but much more largely just questions that relate to one or the other. Getting certain columns in bash The interaction of TeX and Lua can be quite delicate at times.  While the former has category codes and tokens, the latter has escape sequences and datatypes.  Mixing the disparate concepts of these two worlds can lead to unexpected behaviour which favours common errors, known as gotchas. In the community wiki answer below you can find an overview of the common mistakes that people make when getting to grips with LuaTeX. Let $\displaystyle f$ be differentiable, $\displaystyle f(x)=0$ for $|x| \geq 10 $ and $g(x)=\sum_{k \in \mathbb Z}f(x+k).$ List of apps ever downloaded