I have a few questions about setting a variable equal to another variable in JavaScript.  Let's say we create an object, a and set b = a.  var a = {   fname: "Jon",   lname: "Smith",   age: 50 }  var b = a;   I understand that if we change one of a's properties b will also be changed because when we set b = a we don't clone a's data, but rather create a reference to a's data. For example if we set a.fname = "Sarah", the new value of b.fname will be "Sarah".  If we try to "clear" a though by setting a = {}, object b will remain unchanged. I don't understand why manipulating an object in this way produces a different result than in the 1st example.    Also I have a question about the following scenario.   var x = 10; var z = x;   If we then set x = 20, the value of z remains unchanged. Based on the behavior described in my 1st question, one would think that the new value of z would reflect the new value of x. Could someone please explain what I am missing here?  Thank You!
The primitive types (number, string, etc.) are passed by value, but objects are unknown, because they can be both passed-by-value (in case we consider that a variable holding an object is in fact a reference to the object) and passed-by-reference (when we consider that the variable to the object holds the object itself).  Although it doesn't really matter at the end, I want to know what is the correct way to present the arguments passing conventions. Is there an excerpt from JavaScript specification, which defines what should be the semantics regarding this?
Number of automorphisms of a direct product of two cyclic $p$-groups When to use icons vs. icons with text vs. just text links? Are there any rules on when to use icons vs. icons with text vs. just text links in a web application?  For example:    vs.   save  vs.  save    Extra question: Is  save -or- save  preferable? Which JDK version is compatible with Netbeans on Ubuntu? I'm trying to install Netbeans on my Ubuntu. It was successfully installed but was unable to create new projects or new files. I have installed JDK 12 and then I removed it because I found here a solution that recommended removal of latest versions of JDK and set JDK 8 as default. I did what solution said but now I can't install JDK 8. It is showing me this error message:   E: Package 'oracle-java8-installer' has no installation candidate    So I started searching on the Internet about the solution and I found that "Oracle Java (JDK) 8 Installer PPA (DISCONTINUED)".   What should I do now? I am trying to include a figure into LaTeX from a paper originally created using MS Word. I have already converted all the text/equations into LaTeX but I can't figure out how to get the figures over without re-drawing them using LaTeX code (which I do not want to do). The image is a plain box (like a tabular) one row by 7 columns with numbers inside each cell. Then I inserted arrows of varying length above and below the box (several short ones and one much longer).    I am trying to use the  package with the \includegraphics command.   I copied the figure (box and arrows) from my original article into a blank Word doc. The figure only takes up the first 4 or 5 lines of the blank document. I then selected/highlighted the image and printed the selection using 'PDFCreator'. This allowed me to save the image as a .eps file. I then copied and pasted the eps file into the folder where all my .tex files are saved.  When I compile the document using pdftexify there is a blank space where the image should be. In the console I get the following message when I compile the document:  [27] &lt;Fig3-eps-converted-to.pdf, id =105, 391.4625pt x 74.2774pt&gt; &lt;use Fig3-eps-converted-to.pdf&gt; Overfull \hbox 1.46153pt too wide) in paragraph at lines 511--516 []   My code looks like this:  \documentclass[12pt]{article}  \usepackage{graphicx} \usepackage{epstopdf} \begin{document}  %Text  \includegraphics{fig3.eps}  %text  \end{document}   I have read the sections on graphics in 'LaTeX: A Document Preparation System' and 'The Not So Short Introduction to LaTeX2e' but I still can't figure this out. Should I maybe use a PNG image since it is a pretty basic figure? Any advice on how to properly transfer images from a word doc to .eps format and/or how to get those .eps files into LaTeX properly would be a huge help. How to find out if my system is i386 or x86_64 before installing Ubuntu? I am using Windows as of now and want to install Ubuntu. I want to find out if my system is i386 or x86_64? How do I do that? I always wondered if children who graduate from Hogwarts have an education that is actually worth while in the real world.  Do the children learn math and English?  I can see History of Magic as practical. I know of Arithmancy, but that's the study of the magical properties of numbers, not math.   Since Hogsmead is one of the very last all-magical towns, it's a fair assumption that a majority of the students at Hogwarts will be living in non-magical towns or cities. If practical classes (like math or English) aren't taught, then how do these students function in the non-magical cities? The value of a, b and c for this integral Find out the value of $a, b$ and $c$, for which $$ \lim _{x\to 0}\:\:\frac{1}{x^5}\left(\int _0^x\:\left(a+b \cos\left(t\right)+c \cos\left(2t\right)\right)dt\right)=\frac{1}{5} $$  My first thought was to separate the integral into multiple ones because i thought that it is pretty clear that each integral is a common one and a,b,c are constants and can be taken out . After I solved the integral, that's where I had the problem. I couldn't do the limit of the result that I've got in order to find out the value of $a,b$ and $c$ . Why isn't the center of the galaxy "younger" than the outer parts? I understand that time is relative for all but as I understand it, time flows at a slower rate for objects that are either moving faster or objects that are near larger masses than for those that are slower or further from mass.  So, the illustrative example I always see is that if I were to leave earth and fly around at near light speed for a while or go into orbit around a black hole the time I experience would be substantially shorter than for those I left behind at home on earth and I'd come back to find that I've only aged however long I felt I was gone by my own clock but that on Earth substantially more time would have elapsed.  Following through on this model, the stars in orbit around the black hole at the center of the Milky Way are aging much much slower (relative to us), right?  So does it not follow that the center of the galaxy is some appreciable (I have no idea how to go about putting this in an equation so will avoid guessing at the difference) amount "younger" than the stuff further away from the center?   If this is not true, could someone please explain why not, and if it is true, can someone please point me to where I can calculate the age of the center of the galaxy :-)  And to be clear... what I'm asking is... if there was an atomic clock that appeared at the center of the galaxy when the center was first formed, and we brought it through a worm hole to earth today - how much time would have elapsed on that clock vs. the age we recon the galaxy currently is? (13.2 billion years) Exponential of the differential operator I am not sure whether this question is even well-posed. But today I learnt that $e^Df(x) = f(x+1)$ where $D$ is differential operator and  $$e^D \triangleq \sum_{i=0}^{\infty} \frac{D^i}{i!}.$$  (ref. )  So I was curious as to whether the differential equation  $$\frac{df(t)}{dt} = e^Df(t) = f(t+1)$$  has any solutions apart from $f = 0$? The overly simplified explanation I'm giving myself right now is  causes the opposite of what gravity does, that's why the universe is expanding. Now where gravity is a force, why dark energy is "energy"? Why it's not called "Dark Force" instead? I think I must be missing something here. Can I have multiple background images using CSS? If you open any of localized meta site in browser's private mode, e.g.  you will see untranslated text on the top right corner:        This message is not found in Transifex, hence unable to localize.  Related bug report on ruSO.meta: Router to router setup works fine with straight cable up to 2-3 meter it is not working for 45 meter why? No space following macro without argument How to integrate OpenCV Manager in Android App I want to construct a complex power series with the radius of convergence $R=1$ that diverges in:  1) $k$ points on the circle $\{|z|=1\}$.  2) countable number of points on the circle  I have already crafted series that converges on the whole circle and diverges on the whole circle.  Can anybody help with the problem?  Update: I have googled a series $\sum{\frac{z^{kn}}{kn}}$ that is an answer for 1). Though I still need help for the countable case. Most accurate Map of Arda before Beleriand was lost I am making my own Lotr themed Risk game and I am having trouble finding a very accurate map of Arda before beleriand was lost. This map should include Valinor and Numenor as well.  The best I can find so far appears to be a map from David Day's "Tolkien Bestiary"  I hope this is not a bad question, I am new. GCD of the already GCD Can I mention professors' names in the statement of purpose? For PhD applications, I have mentioned that I am interested in some research areas. Besides, I am thinking about mentioning some professors' names, so that it shows I have read their websites and I am not just sending out generic statements applicable to many schools.  But is it good to mention some professors' names in the statement of purpose, if I don't know them personally? In what cases is it good, and in what cases it isn't?  For example, is it good to only mention    those whose research directions are aligned with my research interests, or/and those whose books or notes I have heard of, or better, might have read some parts of, or/and those who are already established and famous (such as having certain titles), or/and those that are directing the PhD graduate programs, or/and those that are heads of the departments?    What will other professors who are not mentioned think? How will you do, if it were you? Limit memory usage for a single Linux process I'm running pdftoppm to convert a user-provided PDF into a 300DPI image.  This works great, except if the user provides an PDF with a very large page size.  pdftoppm will allocate enough memory to hold a 300DPI image of that size in memory, which for a 100 inch square page is 100*300 * 100*300 * 4 bytes per pixel = 3.5GB.  A malicious user could just give me a silly-large PDF and cause all kinds of problems.  So what I'd like to do is put some kind of hard limit on memory usage for a child process I'm about to run--just have the process die if it tries to allocate more than, say, 500MB of memory.  Is that possible?  I don't think ulimit can be used for this, but is there a one-process equivalent?