Where to put JavaScript
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What are the differences in implementing interfaces implicitly and explicitly in C#?  When should you use implicit and when should you use explicit?  Are there any pros and/or cons to one or the other?    Microsoft's official guidelines (from first edition ) states that using explicit implementations are not recommended, since it gives the code unexpected behaviour.  I think this guideline is very valid in a pre-IoC-time, when you don't pass things around as interfaces.  Could anyone touch on that aspect as well? Is a general GRE score of X sufficient for entry to postgraduate degree Y? Question: I got general GRE scores of VR (verbal reasoning), QR (quantitative reasoning), and AW (analytical writing).  Is this a good score to apply for entry to postgraduate degree in field X?  How will this score look to the selection committee?    Note: This is an intentionally generic GRE question (with unspecified scores and field of study) which is intended as a template for a large number of questions asked on this forum regarding evaluating the scores on the general GRE test (e.g., , , , , , , , and ).  This question seeks answers that are applicable for an applicant for graduate-level programs in any field, based on any scores in the GRE general test.  The goal of this question is to provide a general reference to avoid the need for specific questions with particular scores/field of study. $\sum \cos$ when angles are in arithmetic progression Possible Duplicate:          Prove $$\cos(\alpha) + \cos(\alpha + \beta) + \cos(\alpha + 2\beta) + \dots + \cos[\alpha + (n-1)\beta] = \frac{\cos(\alpha + \frac{n-1}{2}\beta) \cdot \sin\frac{n\beta}{2}}{\sin\frac{\beta}{2}} $$ What does it mean when it says under a journal article that it has been communicated by "XYZ" where XYZ is not the author but some other scholar with a very strong reputation? What is the relationship to the actual author and/or the content? Is this some sort of seal of approval to get results out and known quickly? (I am specifically wondering in the context of mathematics and mathematical physics.) How to fix "-5 No address associated with hostname error" while updating? How do you make Ubuntu accept files sent over bluetooth Which of these sentences is correct, and why?   "What if the Moon was a Disco ball?" or  "What if the Moon were a Disco ball?" TikZ \foreach loop with macro-defined list I have a small problem with the TikZ \foreach loop whenever the list, over which we loop, is defined my a macro. The following code example will show my problem:  \documentclass{scrartcl} \usepackage[utf8]{inputenc} \usepackage{tikz}  \begin{document} Picture one:  \begin{tikzpicture} \foreach \x/\y in {1.0/2.0, 3.0/4.0} \node[draw] at (\x,\y) {\x--\y}; \end{tikzpicture}  Picture two:  \newcommand{\mymacro}{1.0/2.0, 3.0/4.0} \begin{tikzpicture} \foreach \x/\y in {\mymacro} \node[draw] at (\x,\y) {\x--\y}; \end{tikzpicture} \end{document}   The expected result is that both images should look the same. But in the second image, I only get one node - and both \x and \y are each time expanded to 1.0/2.0, 3.0/4.0. I hope someone can help. Why GCP Kubernetes Node host location for europe-north1 seems to be in US? I am new to both Google Cloud Platform and K8s. I have launched Kubernetes cluster in GCP and chosen europe-north1 as the region (europe-north1-a as the zone).   When I try to run my application on this cluster it fails because it expects the application to run in EU region. I added IP and Geo check (using GeoLite database () and AWS IP check tool ()) into my application and they tell me that the host is located in US.  Have I perhaps missed some GCP/K8s configuration option or is this because the europe-north1 region is still quite new and the IP addresses do not correctly show that they are located in EU? In which case I should direct this question to Google? Derivatives: enter "evaluated at" vertical bar with multiple values as subscripts Sorry for the long title, but how do I enter evaluated at (for a derivative), with multiple valuation criteria at the bottom of the the big | line?  Thanks! I know references are syntactic sugar, so code is easier to read and write. But what is the difference between a pointer variable and a reference variable? Resolve build errors due to circular dependency amongst classes I often find myself in a situation where I am facing multiple compilation/linker errors in a C++ project due to some bad design decisions (made by someone else :) ) which lead to circular dependencies between C++ classes in different header files (can happen also in the same file). But fortunately(?) this doesn't happen often enough for me to remember the solution to this problem for the next time it happens again.  So for the purposes of easy recall in the future I am going to post a representative problem and a solution along with it. Better solutions are of-course welcome.     A.h  class B; class A {     int _val;     B *_b; public:      A(int val)         :_val(val)     {     }      void SetB(B *b)     {         _b = b;         _b-&gt;Print(); // COMPILER ERROR: C2027: use of undefined type 'B'     }      void Print()     {         cout&lt;&lt;"Type:A val="&lt;&lt;_val&lt;&lt;endl;     } };       B.h  #include "A.h" class B {     double _val;     A* _a; public:      B(double val)         :_val(val)     {     }      void SetA(A *a)     {         _a = a;         _a-&gt;Print();     }      void Print()     {         cout&lt;&lt;"Type:B val="&lt;&lt;_val&lt;&lt;endl;     } };       main.cpp  #include "B.h" #include &lt;iostream&gt;  int main(int argc, char* argv[]) {     A a(10);     B b(3.14);     a.Print();     a.SetB(&amp;b);     b.Print();     b.SetA(&amp;a);     return 0; } How do I sudo a command in a script without being asked for a password? Started new job. Rollover previous employer 401k to new 401k, IRA or Roth IRA? I recently started a new job and have a 401k from my previous employer that I don't know what to do with.  Should I roll it into my new employer's 401k, a traditional IRA or a Roth IRA? How come everyone easily takes or say the name of "Voldemort" without any fear in Scorpius's world? For example, if I have a lens that is 16mm-50mm, which focal length would be the closest to the human eye's view? (I don't have a camera yet, so I'm just curious.)   Would 50mm be more zoomed in than "normal"?  I imagine 16mm would be wider than the normal human point of view? How to add Lat/long columns to a point layer which is not in WGS84? I need to extract the Lat/long coordinates of the centroids of districts. My QGIS project SCR and the different layers have all been set on "WGS 84 / UTM zone 18N".   I've created the centroids using the usual tool. I could then extracted the coordinates using the "Vector > Geometry Tools > Export/Add Geometry Columns", or saving the layer in CSV typing "GEOMETRY=AS_XY" in the "Layers" part of the "OGR creation options".  Nevertheless, both methods output Cartesian coordinates, whereas I need Lat/long coordinates. Assume you have a flat table that stores an ordered tree hierarchy:  Id   Name         ParentId   Order  1   'Node 1'            0      10  2   'Node 1.1'          1      10  3   'Node 2'            0      20  4   'Node 1.1.1'        2      10  5   'Node 2.1'          3      10  6   'Node 1.2'          1      20   Here's a diagram, where we have [id] Name.  Root node 0 is fictional.                          [0] ROOT                           /    \                [1] Node 1          [3] Node 2               /       \                   \     [2] Node 1.1     [6] Node 1.2      [5] Node 2.1           /            [4] Node 1.1.1   What minimalistic approach would you use to output that to HTML (or text, for that matter) as a correctly ordered, correctly indented tree?   Assume further you only have basic data structures (arrays and hashmaps), no fancy objects with parent/children references, no ORM, no framework, just your two hands. The table is represented as a result set, which can be accessed randomly.   Pseudo code or plain English is okay, this is purely a conceptional question.  Bonus question: Is there a fundamentally better way to store a tree structure like this in a RDBMS?    EDITS AND ADDITIONS  To answer one commenter's ('s) question: A root node is not necessary, because it is never going to be displayed anyway. ParentId = 0 is the convention to express "these are top level". The Order column defines how nodes with the same parent are going to be sorted.  The "result set" I spoke of can be pictured as an array of hashmaps (to stay in that terminology). For my example was meant to be already there. Some answers go the extra mile and construct it first, but thats okay.  The tree can be arbitrarily deep. Each node can have N children. I did not exactly have a "millions of entries" tree in mind, though.  Don't mistake my choice of node naming ('Node 1.1.1') for something to rely on. The nodes could equally well be called 'Frank' or 'Bob', no naming structure is implied, this was merely to make it readable.  I have posted my own solution so you guys can pull it to pieces. rent a car, rent out a car, hire a car English not my native language. I'm trying to understand what would be correct in British English.  If I want to use a car for some time. I can say, "I want to rent a car". But from my knowledge there may be a  misunderstanding. I can say the same words if I want to give a car to someone to use for some time and I want to receive payment.  So what would be correct and not misunderstanding?   1) I want to use a car for some time = "I want to hire a car" 2) I want to give a car to someone to use for some time = "rent out a car"   Is my understanding correct? What would make a question popular with high views? I was wondering what might be making my questions less attractive to users?  I get very low views most of the time. What should be done to increase a question's popularity?