Understanding what this for loop will do
How do I use the conditional (ternary) operator?
Did all Headmasters get a portrait in Hogwarts? Throughout the Harry Potter series, we see that deceased Headmasters of the school get a semi-sentient portrait of themselves in the Headmaster's Office, at the service of the current Headmaster. Do all Headmasters get a portrait? What are the conditions of getting one? For instance, there are a couple of times when Dumbledore is temporarily deposed as Headmaster: Dolores Umbridge takes over the job in Order of the Phoenix, and Minerva McGonagall takes the job in Chamber of Secrets and Half Blood Prince. Will Umbridge and McGonagall have portraits in the Headmaster's Office when they expire? For some reason, I can run halt, poweroff, shutdown, and reboot as a regular user without root. How can I fix this? Is it something to do with user groups, or is it a seting somewhere? What does string theory predict for the singularity inside a black hole? The usual explanation for what's going on inside a black hole goes something like "General Relativity predicts a singularity with infinite curvature, but when matters gets so tightly compressed we should expect quantum effects to become important, so the singularity will probably be blurred". Authors then proceed to say that we need a quantum theory of gravity to answer such things, and quickly abandon the subject.  Well, while we don't have an experimentally confirmed quantum theory of gravity, we do have a speculative one, string theory. What does it say about singularities? Are they smeared out like the books say? Do they remain points (or rings for a rotating black hole) with infinite curvature and density? Do we not know? Can I use the Twig template engine? I do a lot of  development and I like their templating language. , the , looks very much like it.  How can I use Twig in Drupal 7 or even Drupal 6? Where to put the escape characters? I've tried to change my prompt by editing .bashrc:  export PS1="\e[0;32m[\u@\h \W]\$ \e[m"   This seems to work, but ctrl-r to access reverse history ends up with my typing not appearing in the same place as it will be interpreted (like ). It is fine when using the up or down arrows to select previous commands though.  I've had a look at that question, but can't seem to work out where to apply the escape characters in my prompt. I've tried a few combinations but then I break normal text typing functionality or simple back/forwards through history.  If you could include an explanation of which instances of characters need escaping and why, that would help me (and hopefully others) learn. "Activity" tab for the Community user's network profile sometimes leads to a server error Can SQL Server's Page Life Expectancy be too high? I've read several articles about SQL Server's Page Life Expectancy and what it means and what kind of information you can glean from it. In most of these articles that I've read, a common, healthy PLE value is somewhere around 1000-2000 seconds. I've read that getting down to around 300 seconds can mean you're likely low on RAM.  I recently just upgraded our hardware to have 64GB of RAM, up from 14GB. On the 14GB my PLE was around 300 seconds, and I was having a lot of 5-6 memory grants pending per second. So, that was bad and I increased the RAM. Now, my PLE is much, much higher around 5000 seconds, and no more pending memory grants. I've seen it 7000 seconds, if I recall. This is much higher than anything I've read.  Can a high PLE be a bad thing? Or is it the higher the better?  EDIT: I'm sorry, my PLE wasn't 7000 seconds, it was 70,000 seconds! Although, at the moment it is down to around 7000.     The database size is around 160GB. A few tables have 5+ million rows. max_server_memory is set to 2147483647. Method overloading in Objective-C? When there are several cottages each with several tariffs (depending on the season), should the plural be "cottage tariffs" or "cottages tariffs"?  For context, this is to be a section title on a website renting out the cottages.  An explanation of the grammatical rules would be helpful. What is a socket? Why is my find not recursive? I am running the following command, but it is not performed recursively:  find . -name *.java   I know there are java files further down in the current directory but it is performing the find on the current directory only. I am using OS X, 10.9. How do you get the index of the current iteration of a foreach loop? Given two functions $f$ and $g$, is there a formula for the Fourier transform of $f \circ g$ in terms of the Fourier transforms of $f$ and $g$ individually?  I know you can do this for the sum, the product and the convolution of two functions. But I haven't seen a formula for the composition of two functions. Zero visitors? What happened to site analytics about a week ago? How can I prove the formula for calculating successive entries in a given row of Pascal's triangle? I've found in Wikipedia the formula for calculating an individual row in Pascal's Triangle: $$v_c = v_{c-1}\left(\frac{r-c}{c}\right).$$ where $r = \mathrm{row}+1$, $c$ is the column starting from $0$ on left and $v_0 = 1$.  Now, I've tried to do by hand and it works,  but I don't understand how to find this magic formula when I don't have access to Wikipedia...:) What's the term for design ala "object.method1().method2().method3()"? What's the term for this design?  object.method1().method2().method3()   ..when all methods return *this?  I found the term for this a while ago, but lost it meanwhile. I have no clue how to search for this on google :) Also if anyone can think of a better title for the question, feel free to change it.  Thanks  Update-Gishu: After reading about it, I feel that your question is misleading w.r.t. code snippet provided.. (Feel free to rollback)  Method Chaining  object.method1().method2().method3()   Fluent Interfaces  private void makeFluent(Customer customer) {         customer.newOrder()                 .with(6, "TAL")                 .with(5, "HPK").skippable()                 .with(3, "LGV")                 .priorityRush();     } Laptop Overheating. Is there a way to cool it? I have a laptop that's running on the following:   MSI MS-1634X motherboard AMD Turion X2 TL-66 CPU ATI Mobility Radeon HD2600   It keeps overheating, especially when I do something more CPU and GPU-intensive such as games. I've tried SpeedFan and Notebook Hardware Control and neither are able to help control my fans. I also have a Targus Chillmat for my laptop which helps cool down my laptop, but it still overheats. Are there any fan controlling programs that I could use to maybe turn up the RPMs on my fans or any other ways to cool down my laptop? My laptop runs pretty hot, maybe 80c core when being used, not even intensively. The Hard drive stays cool though, close to 35c.  Any help is appreciated. Thanks! Change the display scaling on the fly I'm looking for a keyboard shortcut or a CLI instruction to change the display scale on the fly. Seems there's nothing in compiz-config manager to handle this? Comparing $\pi^e$ and $e^\pi$ without calculating them Adding tags to files in OS X: How to use, where are tags stored, and will they work on a network? I've heard it is possible to add tags to a file's meta data in OS X, and have Spotlight search through such tags.   In a nutshell, how would one access this feature in Finder &ndash; not Spotlight (Command+Space) &ndash; but the adding of tags themselves? Where are these tags stored?  Do they go in .DS_Store (I tend to delete those!) or elsewhere in the filesystem? Does this tagging mechanism work on removable drives?  What are the requirements? Does this tagging mechanism work over a network share?  I have some Windows SMB network shares at home that I frequently store files on.  Would it work on those or is another configuration required? Aside from Spotlight, are there any command-line tools for searching through or accessing the tag data for files?   Thank you!