So I was thinking about what's more efficient, making a number by directly adding them as a string to each other, or string.Formatting them.  So I made a little code piece:      private static void measuringStuff()     {         Stopwatch stw = new Stopwatch();         Random random = new Random();         string a;          stw.Start();         for (int i = 0; i &lt; 10000000; i++)         {             a = random.Next(10) + "" + random.Next(10);         }         stw.Stop();         Console.WriteLine("#+\"\"+#: " + stw.ElapsedMilliseconds);          stw.Reset();         stw.Start();         for (int i = 0; i &lt; 10000000; i++)         {             a = string.Format("{0}{1}", random.Next(10), random.Next(10));         }         stw.Stop();         Console.WriteLine("string.Format: " + stw.ElapsedMilliseconds);     }   And it turns out:  # + "" + #: 1928 string.Format: 2667   Why?
I've got a small piece of code that is parsing an index value to determine a cell input into Excel.  It's got me thinking...  What's the difference between   xlsSheet.Write("C" + rowIndex.ToString(), null, title);   and  xlsSheet.Write(string.Format("C{0}", rowIndex), null, title);   Is one "better" than the other? And why?
UK Visa Status check I have a US Green Card and applied for UK visa (Travel Visa) last month but haven't heard anything back from the New York Office. I am travelling on the 19th and am really concerned. They don't have any phone no. or email other than NEYOZVisaInfo@fco.gov.uk (it says incoming mail cannot be monitored).  Please assist. How to Create a Half-Turn Staircase? I would like to create a half-turn staircase without a landing. Is there an easy way to accomplish this without having to manually calculate and create each step individually?  Here’s an image similar to what I would like to achive:    I have found the Archimesh add-on including . While I can bend the created stairs, I haven’t found any way to get anywhere close to the image above. My stairs just always look out of shape and I don’t know how to get the outline of the staircase into a square.  I should mention that I only have very little experience with Blender modeling, so it’s well possible that I’m just missing some curve modification basics. Perhaps Archimesh is also the wrong approach for this in the first place? Why are there unwanted white lines appearing in a PDF print proof? I designed a christmas card and I normally print it on vista print.  When I ask for a print proof the outlines show. They don’t show when I print it at home.  Why are there unwanted white lines appearing in this PDF print proof and how can I solve this problem? Easiest way to solve $y''+y=\frac{1}{\cos x}$ What does 'per unit frequency' refer to? We were discussing Kirchoff's theorem on blackbody radiation in class today and the equation was: $$e_{f}= J(f,T)$$  $e_f$ was defined as power per unit area per unit frequency. What does per unit frequency refer to here? I know what per unit time means but don't understand 'per unit frequency'. 12.04.3 can start only after I press "resume" in rescue mode (every boot) - problem with Nvidia driver I've tried to install maybe ten Linux distros on my new PC, and every time I have problems with video drivers: black screen or visual artefacts.  I was able to install only Ubuntu 12.04.3 64-bit, but also with problems: black screen on startup (sometimes all was normal when I used Live mode before install, sometimes I was not able to load Live Mode - Ubuntu says that I have problems with video and gives me a choice with four elements, one of them "use safe graphics mode", but I even can't choose this - the system is frozen).   In tty I installed nvidia-current, but it didn't help me. Every boot I need to press ESC and enter rescue mode and just press Resume and after this the system boots normally. If I try to do a normal restart I get a black screen after Ubuntu logo again.  I tried switching nvidia driver in the options - I have version 319-updates and version 319 [Recommended], but neither works.  I have Palit GeForce GTX650, all updates. Are there any series whose convergence is unknown? Are there any infinite series about which we don't know whether it converges or not? Or are the convergence tests exhaustive, so that in the hands of a competent mathematician any series will eventually be shown to converge or diverge? EDIT: People were kind enough to point out that without imposing restrictions on the terms it's trivial to find such &quot;open problem&quot; sequences. So, to clarify, what I had in mind were sequences whose terms are composed of &quot;simple&quot; functions, the kind you would find in an introductory calculus text: exponential, factorial, etc. Is the topological product $\Pi \{G_\alpha: \alpha < \kappa\} $ a topological group? How to make the taskbar blink my application like Messenger does when a new message arrive? Is there an API call in .NET or a native DLL that I can use to create similar behaviour as Windows Live Messenger when a response comes from someone I chat with? I'm planning a trip to recover a motorcycle from a distant city. The ideal trip would be flying to that location and coming back riding the bike, but that would require me to transport my riding gear with me in the plane: Leathers, boots, gloves, back protector and crash helmet.  All this is bulky and expensive stuff, and a crash helmet may be damaged if dropped or hit hard.   I don't expect any airline to allow me a crash helmet as hand luggage; and wearing it all the time is out of the question :-)   To complicate things, I would be coming back riding the bike, so any hard suitcase would have to be left behind.   How do people normally transport that kind of stuff? Find in Files: Search all code in Team Foundation Server Geometry with Trigonometry From the given figure, prove that      $$\cot\ \theta=\cot\ A+\cot\ B+\cot\ C$$     I could not even start to the first point. Please help me to solve this.  Thanks in advance How long was Luke Skywalker's training with Yoda? Are there areas of mathematics (current or future) that cannot be formalized in set theory? I often read that ZFC can formalize "most" of everyday mathematics, but I could never find an example which it cannot. The closest I got is differential geometry (DF), where some article mentions that the translation from concepts of DF into set theory would render it almost "meaningless", in the sense that any intuitions one could have would be lost in the translation. So, if I didn't misunderstand, at least in theory, the translation could be done, so that a future AI machine could prove theorems of differential geometry using set theory. On the other hand, the Stanford Encyclopedia of  Philosophy states that "all of mathematics can be reduced to a formal system of set theory"().   So, the questions are:    Is there any current area of mathematics that could be not formalized within set theory? If so, which ones? and  Is there any reason to think that every math of the future will be always formalizable in set theory? any references to read on the subject are welcomed!   Clarification: by set theory I am not restricting to ZFC, but to any flavor of it, including all additional axioms you want (about large cardinals or any kind) Is there an expression to indicate the strategy of wearing someone down with numerous small irritations? I would use rope-a-dope, but it's got connotations of pretending to lose that I don't need. I'm trying to describe the behavior of someone who sends twenty detailed emails a day about various projects, and the recipient of his emails has finally gotten tired of trying to parse them, so the recipient just agrees to whatever he proposes. I'd like an expression that evokes both outward earnestness and hidden creepiness, like Uriah Heep, Dickens's "Humble servant" with veiled ambition, who overdoes it with professions of humility until he's in power. Water torture would work, but comes too close to a more racist expression that I'm not comfortable with. Sum of nilpotent and element is a unit in ring? I can't tell where I went wrong, am still a beginner.    Let N be a nilpotent in a commutive ring , let X be any element.   I'll will be showing X + N is a unit .   Assume Y(X+N) =1   Then YX(N^n-1) =  N^n-1   Multiplying both side by  X+N   We get X(N^n-1) =  X(N^n-1)  Thus nilpotent summed with any element gives unit. How do you overlay an image on a shader in Cycles? Short story (+radio play?) in which astronauts outside their ship slowly drift apart in space Looking for a short story in which the crew of a spaceship for some reason find themselves outside the ship, drifting apart in outer space. They can communicate via their radios but are individually drifting apart.  One by one, they lose communication as they drift further away from each other.  Might have also been adapted into a radio play? Limit of the sequence $a_n=\sqrt[n+1]{(n+1)!}-\sqrt[n]{n!}$ I downvoted  and now really can't say why, so I wanted to remove my downvote. However, I get the message:  You last voted on this question yesterday Your vote is now locked in unless this question is edited  Why is this? I don't think I voted on it multiple times, and even when I did, I can change my mind, can't I?