So I need to locate where the "Nut" string is stored at. I thought my code would work just fine but obvious the ide just keep throwing me an error.    Random rd = new Random(); String[] hidingSpots = new String[100]; hidingSpots[rd.nextInt(hidingSpots.length)] = "Nut"; System.out.println("The nut has been hidden ..."); int nutLocation = 0; while (nutLocation &lt; hidingSpots.length) {     if (hidingSpots[nutLocation].equals("Nut")) {         System.out.println("Found it! It's in spot# " + hidingSpots[nutLocation]);     }     nutLocation++; }
What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?
Norm is sup of inner products (proof). Let $V$ be a vector space with an inner product $\langle.,. \rangle$ and associated norm $|| . ||$ Then:    Could I have a proof of this fact? Where is the operator panel in Blender 2.8? The tutorial I read is based on 2.79. So I'm not sure if it's still the same name in 2.8. But I can't find anything providing similar functionalities. Ubuntu 20.04 brightness adjust not working I am unable to adjust brightness levels through Gnome. I had the same issue with 18.04 but it was resolved there (honestly, I can't remember how).  lspci|grep VGA 00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 18)  xrandr --output LVDS-1 --brightness 0.95 &lt;-- this works through the terminal excerpt from /etc/default/grub GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"   Thank you in advance. If rest mass does not change with $v$ then why is infinite energy required to accelerate an object to the speed of light? I know that as the velocity increases, the mass of the object also increases so it becomes tougher and tougher to move the object which ultimately leads to a requirement of infinite energy to accelerate an object to the speed of light. But I have a doubt.  As far as I know only the observable mass (Relativistic mass) increases but not the Proper Mass or Intrinsic Mass, right? The actual mass of the object will remain the same. So if the actual mass ($m_0)$ remains the same and only the observable mass increases, why is more and more energy required? I know that even if the object exceeds the speed of light, we will not be able to say that it is moving faster than the speed of light but is it possible to make it move faster than light?  If rest mass does not change with $v$ then why is infinite energy required to accelerate an object to the speed of light?  I quote Igor Ivanov (a stackexchange user from this question ) to give an insight into my question.     The mass (the true mass which physicists actually deal with when they calculate something concerning relativistic particles) does not change with velocity. The mass (the true mass!) is an intrinsic property of a body, and it does not depends on the observer's frame of reference. I strongly suggest to  popular article by Lev Okun, where he calls the concept of relativistic mass a "pedagogical virus".   EDIT  After reading the answers I have a doubt.  SO can I say that only the overall energy of the system increases while the mass remains constant? But then if mass remains constant, then why is more and more energy gradually required? I mean there should be a reason for that requirement of infinite energy. I have many tags marked as "interesting" and others as "ignored". (I use Java at work, I'm a Cocoa guy by night, any anything dealing with Windows/.NET/C# simply doesn't apply to me.) When tags are added to the list in the right navbar, they appear in the order in which they were added. There are several problems with this:   It can be difficult to visually locate a tag quickly, unless you have memorized its location. The tags appear as the same gray boxes like everywhere on SO, but with a small "x" afterward, and they wrap based on size. This tends to leave a ragged right margin and wasted space. Ordering based on when the tag was added is not always the most intuitive default. Various users might prefer to view them alphabetically, by popularity, recent activity, etc.   It would be nice to introduce a tabbed interface to switch between various orderings, and remember the value in the cookie, profile, etc. Coupled with this, perhaps users could specify a custom ordering that works best for them? (Currently the workaround is to copy all the tag names, remove them all, and re-add them in the desired order, but this is obviously annoying.)  Thoughts? What are the rules of parallelism? I've been reading a lot about it since yesterday and all I encounter is "They must have the same grammatical form"? What does this exactly mean?  I know how to make parallel sentences with gerunds. The things get trickier when it comes to using modifiers.  For example:     I love using the phone that you bought me and the computer.   On the left side of the conjunction there is a noun phrase that consists of an article + noun + another modifier and on the right side there is an article + noun.  They are both noun phrases but the first one has additional modifier. Is that still considered a parallel sentence?  Another example:     I like to swim and to feel good.   Here on the right side of the conjunction there is an infinitive and on the left side there is an infinitive + complement? Is that parallel? Escape velocity from Earth E: Malformed entry 54 in list file /etc/apt/sources.list (Component) How do I allow HTTPS for Apache on localhost? How do I catalog files on several external hard drives that I want to store off-line? I have quite a few external hard drives that I want to store off-line, and possibly off-site.  The contents is not saved in a structured manner, however; basically  there's lots of project data for lots of projects.  Is there any software for Windows XP that will catalog all the hard drives, so I can search the catalog, find the files, and get the ID of the disk that has the content? Where can a tourist apply for a UK Visitor (standard) Visa? Command prompt as SYSTEM user (Windows 7) How can I get a command prompt as the SYSTEM user on Windows&nbsp;7?  Context: I'm testing a computer startup script, and I need to figure out the behavior of a command when run as SYSTEM rather than my user account.  I've seen ways to do this with at and psexec, but those methods only appear to work on Windows&nbsp;XP or Windows&nbsp;Vista.  I'm using Windows&nbsp;7 Pro SP1. Consider the Fibonacci numbers $F(0) = 0; F(1)=1; F(n) = F(n-1) + F(n-2)$.  Prove by induction that for all $n&gt;0$,  $$F(n-1)\cdot F(n+1)- F(n)^2 = (-1)^n$$  I assume $P(n)$ is true and try to show $P(n+1)$ is true, but I got stuck with the algebra. How do we reach $P(n+1)$ from $P(n)$? Also, strong induction may be used instead. "[somebody]'s theme" vs "[somebody] theme" — Saxon genitive dillema When is it required to use 's in phrases like below (examples taken from Wikipedia)?   James Bond theme 007 theme Boba Fett motif Droids motif Yoda's theme ...   Are there any rules for eliding Saxon genitive?  How does the situation change if we have something instead of somebody? Spoiler warning!  During the first escape attempt in Portal 2 (when GLaDOS is still in charge) she opens a door for you which you can choose to go through instead of following Wheatley (the blue-eyed ball). What happens if you go there? Easily measure elapsed time How can I convince hyperref and xindy to play together nicely? Arithmetic progression topology I am using Eclipse 3.3 ("Europa"). Periodically, Eclipse takes an inordinately long time (perhaps forever) to start up. The only thing I can see in the Eclipse log is:       !ENTRY org.eclipse.core.resources 2 10035 2008-10-16 09:47:34.801     !MESSAGE The workspace exited with unsaved changes in the previous session; refreshing workspace to recover changes.   Googling reveals  that I remove the folder:  workspace\.metadata\.plugins\org.eclipse.core.resources\.root\.indexes   This does not appear to have helped.  Short of starting with a new workspace (something which I am not keen to do, as it takes me hours to set up all my projects again properly), is there a way to make Eclipse start up properly? Auto revision summary has wrong plural: "added 1 characters in body" As seen at:           Update: I'm 101% sure the down votes were due to the lack of free hands.    Update 2: likes me, like me not, like me, likes me not... yeah !