java.lang.ArrayIndexOutOfBoundsException: 2
What causes a java.lang.ArrayIndexOutOfBoundsException and how do I prevent it?
Let's say you have the ability to shine some light into a perfectly round sphere and the sphere's interior surface was perfectly smooth and reflective and there was no way for the light to escape.  If you could observe the inside of the sphere, what would you observe? A glow? And would temperature affect the outcome?  Seems silly, it's just something I've always thought about but never spent enough time (until now) to actually find an answer. How to pass Unicode characters as JSP/Servlet request.getParameter? Make square image What is wrong with this query? (Unknown error parsing query) When I run the following query in query editor I get this error.  Error     Unknown error parsing query   Query  SELECT Id, OwnerId,Account.OwnerId FROM Contact where OwnerId = Account.OwnerId limit 100   Does anybody know what the problem is? Eigenvectors of real symmetric matrices are orthogonal If we have a point charge and outside of it we have a non-conducting Gaussian sphere, then Gauss's law says that the net flux should be zero. I agree that the total field lines coming in are equal to the number of field lines coming out, but isn't it true that the magnitude of the electric field at those segments of the sphere where the field is coming in is greater than those where it is coming out? So when we integrate, wouldn't these areas, having a greater electric field, contribute more to the net flux? I don't see why they would cancel each other out. Which is correct, and why?     some days we went on adventures — him maneuvering our scooter, me resting my chin …   or     some days we went on adventures — he maneuvering our scooter, I resting my chin … Does the PHB+1 character-building limit in Adventurers League include spells? I’m thinking of trying out a Hexblade Warlock in Adventurers League, which limits players to PHB+1 for character-building.  The problem I have with this is that the Hexblade is from Xanathar's Guide to Everything, but I really want the booming blade cantrip as well from the Sword Coast Adventurer's Guide. Is this legal in Adventurers League play? I was just reviewing my "capitalization standards" for titles and such and was wondering if there's a macro to do the same thing I'm forced to do by hand nowadays. My personal rules (feel free to disagree/comment on them) are as follows:   the first letter (a number is a letter too for the sake of these rules) always gets capitalized, every word gets capitalized individually, the exception to the rule above (and just the rule above) are  such as prepositions and the like.   In other words: I'd like a capitalization command (like \MakeUppercase) that will capitalize every word not included in a list of words and that will always capitalize the first word of its argument.  Doable?  PS: one such "list" of closed class words (also known as "function words") can be found . Finding the Eclipse Version Number What is the rationale for all comparisons returning false for IEEE754 NaN values? When does SQLiteOpenHelper onCreate() / onUpgrade() run? What is the relationship between ISO, aperture, and shutter speed? I know digital cameras have ISO options, and that ISO is the camera's sensitivity to light, but if you set  higher ISO then you can get a noisy image. I also know there are two other camera options, shutter speed and aperture.   What is the relationship of between them? Is there any equation, or something like that?  For example, if I set the ISO to 640, then how should I set the shutter speed and aperture? Why is using "for...in" for array iteration a bad idea? I've been told not to use for...in with arrays in JavaScript. Why not? Is there a catchall function somewhere that works well for sanitizing user input for SQL injection and XSS attacks, while still allowing certain types of HTML tags? Nth derivative of $x^x$ A few days ago, I was wondering about a series expansion for $$f(x) = \  x^x$$ so I tried taking a couple derivatives. From these I was able to guess at some formulas for the general coefficients of the first few terms of the nth derivative as well as the last term (where I put the terms of the derivative in the order  $$f^{(n)}(x) = c_1x^x + c_2x^{x-1} + c_3x^{x-2}\ + \ ... \ +\ c_nx^{x-(n-1)}$$  Please let me know if there is a general formula for the coefficients as a function of n. In my own fooling around, I found that $$\ln(x)+1$$ appears quite a bit, so I called this $a$ in my work. Since I would like to center my expansion at $1$, and this expression evaluated to $1$, at $x=0$, I was interested in writing my formulas as functions of $n$ and $a$. I found that you get something of the form (this could very well be completely incorrect):  $$f^{(n)}(x) = ax^x + a^{n-2}{\binom n2}x^{x-1} + a^{n-4}(3{\binom n4}-a{\binom n3})x^{x-2}\\ + a^{n-6}(15{\binom n6}-10{\binom n5}a+2{\binom n4}a^2)x^{x-3}\ + \ ... \ +\ (-1)^n(n-2)! \ x^{x-(n-1)}$$  An interesting property that seemed to recur for the various coefficients was  that once I found a recursion formula for the coefficient in question and plugged in my initial value, it always seemed to be the same as taking the integral of the previous coefficient with respect to $a$. That is to say, if I plugged in the nth coefficient (a polynomial of $a$) into my recursion formula for the $(n+1)$th coefficient, this gave me the same result as integrating. In general, as reflected by the few coefficient formulas above,  the formula for the coefficient of $$x^{x-c}$$ where c is an integer such that $$0\le c&lt;n$$ "Stabilized" to a polynomial of a with c terms after the first few applications of the recursion formula. This stabilization occurred when $$n=2c$$ Also, as a direct result of the tentative and incomplete formula I have written above, the first nonzero-value for the coefficient of $$x^{x-c}$$ is $$(-1)^{c+1}(c-1)!$$ and appears in $$f^{(c+1)}(x)$$ If these various properties are indeed true, can anyone explain why this would be the case? I am aware that this function can be expanded using the expansion for $$e^x$$ with $$x\ln(x)$$ in the exponent. This does not strike me as particularly enlightening (let me know if I'm missing something). I am most interested in the coefficients on the binomial coefficients, since these are the only things that stand between me and a general formula for the coefficients (since the form is quite standard). These are: $$1$$ then $$3,-1$$ then $$15, -10,2$$The sum of these coefficients should also give the nth derivative evaluated at zero since $$f(1) = 1$$ and $$a(1) = 1$$  Anyway, please let me know what you think! I am currently stuck due to an inability to brute force my way any further and a complete lack of cleverness. My knowledge of mathematics is quite elementary, so please explain any higher level concepts if they are necessary to explain this problem. How does an attacker's reach interact with the Mounted Combatant feat's ability to force an attack against the mount to target the rider instead? How can I create launchers on my desktop? Looking for a trilogy published around the early 80s.  Insect-like aliens are invading earth.  Humans' brains are placed in robotic bodies.  The protagonist is a child in one of these bodies.  He has to learn how to control the robot &amp; conserve his battery power.  Once train, he can fight back against the aliens using heat-guns + physical attacks.    The aliens are landing/spawning on sites all over the globe.  Part of the plot is discovering a method to disrupt their staging points.  It was probably young-adult oriented.  If anyone remembers this, thank you. When is it appropriate to use the original pronunciation of a foreign word versus the English pronunciation? When reading to an audience, or speaking in conversation, when is it appropriate to use the original pronunciation of a foreign word versus the English pronunciation (assuming you know the appropriate pronunciation for it)? Is it considered rude, or condescending? Or is it considered a mark of being knowledgeable?  One of the things to consider are place names. When referring to Paris, France, should it be pronounced with the silent 'S' as the French would say it, or with the 'S'? Should Hiroshima be pronounced as a Japanese speaker would pronounce it slightly more emphasis on RO, rather than the SHI? Should Mount Pinatubo be pronounced as a Filipino speaker would pronounce it with shorter stronger vowels, or the longer vowels? (e.g. Pi as is 'pick' rather than 'pea'.) Should Wichita be pronounces as the original "shi" rather than the modern "chi"?  Pronounce pesos or sombrero as a Spanish speaker 'eh' or the English 'ay'?  (I can't think of other common words right now that aren't words taken from other languages like hurricane, boondocks, tornado, etc. which I think have (correctly) changed to English pronunciations.)