Why and where should I use Reflection, I understand that you can get acess to the field by it's name but why should I use it?
What is reflection, and why is it useful?  I'm particularly interested in Java, but I assume the principles are the same in any language.
Meaning of hash symbol in pin name I'm reading the datasheet of a PSRAM (available ). In the top-right hand corner all the pins are listed. Some of the pin names end with a hash, e.g. LB#, OE#.  What does the # notation mean for pins? Graphics crop in guest welcome window I don't expect that any user should have noticed this, since only guests will see them.  Well, it seems that the Stack Overflow welcome splash, containing the basic info of the site, is cropped from the bottom.    Please don't mind the sides, I cropped them to fit on the screen. Just on the bottom is my concern. Who was the real "Master Code Breaker"? This may be a very basic question.      Let $R$ be a commutative ring with unity (may be assumed to be an integral domain, if necessary) and $I$ be an ideal of $R$. Assume that $R/I$ is isomorphic to $R$. Does this mean $I=(0)$ ? Lightning tags in beta I came across some lightning tags that are still in beta, ex: lightning:input (Beta) lightning:tabset (Beta) etc  Not sure for how long they were in beta, is it advisable to use them for building UI and deploy to production? Print box drawing characters with pdfLaTeX I need to print some unicode characters (of box drawing family) in my document. I found this  that is very similar to mine but is valid only for XeLaTeX. There is a valid way to do this with pdfLaTeX or I have to use XeLaTeX instead? What can I do if my USB flash drive is write-protected or read-only? How can I change the umask for one command only? How can I interactively execute a command in Linux (zsh, if it matters) with a different umask from the default, for one command only? Perhaps a combination of commands combined in a single line? The new umask should apply only to that command and return to its default value for the next command entered.  Ideally the command would be agnostic to the default umask in force before its entered (in other words, the default umask doesn't have to specified). How to Configure Launcher Placement in Multi-monitor Setup I use a large monitor as primary and laptop screen as secondary. Is it possible to move the launcher to my big monitor or do I have to turn off my laptop monitor?   "Monitor Preferences" (Launcher search -> "Monitors") does not have a way to set the default/primary monitor. nvidia-settings which I just installed says "You do not appear to be using the NVDIA X driver. Please edit your X configuration file (just run nvidia-xconfig as root), and restart the X server.  sudo nvidia-xconfig says sudo: nvidia-xconfig: command not found.  I guess I don't have an AMD driver because I don't have "AMD Catylist Control Center" in the launcher search. What is a "callable"? Nesting HTML- anchor tags Evaluate these infinite products $\prod_{n\geq 2}(1-\frac{1}{n^3})$ and $\prod_{n\geq 1}(1+\frac{1}{n^3})$ What is   $\prod\limits_{n\geq 2}(1-\frac{1}{n^3})=?$ $\prod\limits_{n\geq 1}(1+\frac{1}{n^3})=?$   I am sure about their convergence. But don't know about exact values. Know some bounds as well. For example first one is in interval (2/3,1) and second one is in (2,3). ConTeXt: Flush right formula numbers in cases environment I would like to have the formula numbers of the cases environment flush right like regular formulas (not at a fixed distant from the cases like it is by default with the default setting numberdistance=2.5\emwidth). How can I do that?  \starttext  \startplaceformula     \startformula         \startcases             \NC x = 1 \NR[+]             \NC y = 1 \NR[+]         \stopcases     \stopformula \stopplaceformula  \stoptext     What I want (but with the left bracket):  \starttext  \startplaceformula     \startformula         \startalignment[n=1]             \NC x = 1 \NR[+]             \NC y = 1 \NR[+]         \stopalignment     \stopformula \stopplaceformula  \stoptext Integral of periodic function over the length of the period is the same everywhere Trouble with gradient intuition Dissolve (merge) polygons QGIS based on attribute values only when are adjacent Energy-momentum tensor transformation How do I pipe terminal standard output (stdout) to the clipboard? For example,   Say I want to list the contents of a folder and directly paste them into a chat window for a friend to see.    I realize I could do ls &gt; filename.txt to create a file (filename.txt) with those contents; I'd then have to open or print the file and manually select and copy the text block (which can be annoying/tedious.)  I clearly could also select and copy the output of ls directly from within the terminal window.  It would be much faster/easier to simply pipe standard output to the clipboard.  What terminal command allows me to do this? Unable to upgrade pip Occasionally (very occasionally) when returning to the main page of a site by clicking on the logo I get the following message:     It was not possible to perform this tag search at this time due to an unexpected error.   This is odd because I'm not performing a tag search.  So far this has happened on both Movies &amp; TV and Cooking.  I have heard that others are getting this same message.