I was reading an example about final for Java, and saw something like :  Counter c = new Counter() {   public int count() {     super.count();        return super.count();   } } c.count(); // now count 2   Is there a name for such construct? Is this ever used in practice? Is yes, it is considered a good OOD? A reference or a blog article would be appreciated.
What is the use of anonymous classes in Java? Can we say that usage of anonymous class is one of the advantages of Java?
Execute function when post is published I try to use this function i have created when a post is published for the first time.  function a_new_post($post){   $post_id = $post-&gt;ID;    if ( !get_post_meta( $post_id, 'firstpublish', $single = true ) ) {       // ...run code once       update_post_meta( $post_id, 'firstpublish', true );   } } add_action( 'draft_to_published', 'a_new_post' );   I can't see anything wrong with it, but when i try to create some sample posts i check the database and the field "firstpublished" has not been created.  Does anyone see anything wrong? How do you judge the quality of a journal? Why do first years cross the lake to get to the castle? jQuery 1.9 checkbox not checked second time after once it unchecked The vast majority of intelligent species in the Star Trek universe are bipedal, humanoid creatures.  From the lot I've seen of TOS, TNG, DS9, Voyager, Enterprise, and the movies, it seems that this coincidence goes largely unquestioned.  Metaknowledge grants that it is much easier to have human actors portray human-like beings, and so this was probably done due to budgetary/technological limitations.  However, I'm wondering if an in-universe reason for this was ever given or explored? $n$ balls are thrown randomly into $k$ bins - how many are empty? A large number of variants of this question were already asked here, including these - , , which are close, but none seem to answer my question. Assume that $n$ balls are thrown randomly and independently into $k$ bins.  What is the probability of finding $x$ empty bins? What is the expectation of the number of empty bins? Get and Set Screen Resolution Should I ask questions I already know the answer to and answer them myself? I have two screens on my Windows 8.1 computer (with Classic Shell Start Menu installed). The thing is that I would like to have the taskbar's  (where the clock and all the icons like Skype or Spotify are, at the right) on both of my screens, and not only on the primary one.  Could you help me ? I would like not to install a heavy and paid software like DisplayFusion. Running shell command and capturing the output I did not know that you could find an answer for that. However, I can only use Excel so far to do it.  How to calculate 3.6! by hand? Dense sets in Hilbert space of square summable sequences? Let $l^2 = \{x = (x_n)| x_n \in \mathbb{R}, \sum_{n=1}^{\infty} x_n^2 &lt; \infty\}$  be the Hilbert space of square summable sequences and let $e_k$ denote the $k^{th}$ co-ordinate vector (with $1$ in $k^{th}$ place, $0$ elsewhere). Which of the following subspaces is NOT dense in $l^2$?   span$\{e_1-e_2, e_2-e_3, \ldots\}$ span$\{2e_1-e_2, 2e_2-e_3, \ldots\}$ span$\{e_1-2e_2, e_2-2e_3, \ldots\}$  span$\{e_2, e_3, \ldots\}$   By definition, we have to prove that for any $x \in l^2$ and for any $\epsilon &gt; 0$, there exists $y$ in the respective sets such that $\|x-y\| &lt; \epsilon$. How to proceed further? Show that $\left| \frac{1}{x}-\frac{1}{z} \right| \le \left|\frac{1}{x} - \frac{1}{y} \right| + \left|\frac{1}{y} - \frac{1}{z} \right|$. How to see if SkyDrive is still syncing in windows 8.1? Windows 8 displayed overlay icons on my SkyDrive files, so I could see which files are current and which are in sync.  After I upgraded to Windows 8.1 the files still sync, but I can't see if the files are current or not. The only way is to load a file, check for myself if the latest changes are there (if I remember them) and refresh until the file is synced. Which is a pain! The sync overlay does only show for files which modified locally and are waiting to upload, it does not show up for files which had been changed on the server (other computer) and are waiting to download!!  So how do I get the file sync Status on Windows 8.1? Ubuntu halts after few seconds of starting and nothing works command, virtual terminal, GUI How to learn commutative algebra? What conditions are necessary for a Wither Skeleton to spawn naturally, and can I manipulate those conditions to increase the chance of them spawning?  I want to make a Wither Skeleton spawning pad in the Nether but I'm having trouble finding Wither Skeletons. I've only heard that they spawn in Nether Fortresses. How can I report bugs with or request features for the Stack Exchange mobile apps? I'm using the official Stack Exchange mobile app for iOS or Android, and  My app crashed! It doesn't look good on my new smartphone. It won't run after I updated my device. I noticed another bug. I have an idea for a new feature which is currently not in the app.  How do I report bugs with or request features for the iOS and Android apps? Also:  I've used the built-in functionality of the app to report a bug or submit a feature request. Did I do the right thing? The app prompted me to post on Meta after an error occurred. Should I post about it here? I'm wondering why the latest version is from 2017. I've heard rumors that the apps are no longer supported; is that true? I can't find the app on my device's app store anymore! Where did it go?     We get a lot of bug reports from users about the mobile apps, which are unsupported, and at the moment, there is no centralized Q&amp;A pair for those to be closed as duplicates of (the relevant answers are spread across multiple unrelated questions). This question is an FAQ proposal, to serve as a directly-related duplicate target for those questions. Proving that $\sum\limits_{n = 0}^{2013} a_n z^n \neq 0$ if $a_0 > a_1 > \dots > a_{2013} > 0$ and $|z| \leq 1$ I'm going to teach a preparation course for the complex analysis qualifying exam from my university (which basically consists of me doing some problems from past exams) and I'm trying to solve some questions from previous exams. One of the questions is the following:           Prove that $\displaystyle{\sum_{n = 0}^{2013} a_n z^n \neq 0}$ if the coefficients  satisfy $a_0 &gt; a_1 &gt; \dots &gt; a_{2013} &gt; 0$ and $|z| \leq 1$.      I tried to approach the problem by using the reverse triangle inequality to try to isolate the leading term, which I thought should be the constant coefficient, as follows:  \begin{array} . \left|  \sum_{n = 0}^{2013} a_n z^n \right| &amp;= \left| a_0 +  \sum_{n = 1}^{2013} a_n z^n \right| \\ &amp;\geq |a_0| - \left|  \sum_{n = 1}^{2013} a_n z^n \right|\\ &amp;\geq |a_0| -  \sum_{n = 1}^{2013} |a_n z^n|\\ &amp;\geq a_0 -  \sum_{n = 1}^{2013} a_n |z^n|\\ &amp;\geq a_0 -  \sum_{n = 1}^{2013} a_0 |z^n|\\ &amp;= a_0\left( 1  -  \sum_{n = 1}^{2013} |z^n| \right) \end{array}  Then for $|z| &lt; 1$, we have that this last expression is equal to  $$ a_0\left( 1  -  |z| \frac{|z|^{2013} - 1}{|z| - 1} \right) $$  and my hope was to prove that this was always positive, nevertheless, after failing to prove it, I plotted the expression inside the parenthesis as a function of $|z|$, and found out that it changes sign in the interval $(0, 1)$.  Question  Can my approach somehow be made to work? And if not, how can I prove that the sum $\displaystyle{\sum_{n = 0}^{2013} a_n z^n \neq 0}$ under the given conditions?  Thank you very much for any help. Show that $n$ lines separate the plane into $\frac{n^2+n+2}{2}$ regions Show that $n$ lines separate the plane into  $\frac{n^2+n+2}{2}$ regions if no two of these lines are parallel and no three pass through a common point.   I know we start with the base case, where, if we call the above equation P(n), P(0), for 0 lines would be 0.  But I really have no idea how to begin the inductive step.  How do we know what k+1 we're supposed to arrive at?  Thanks!