I was just checking inner classes and I know we can declaired the private and static inner class however I do not under stand what can we achieve by declaring a inner class private and static.  class OuterClass {      private static class InnerClass{     } }   As this class is private no other class would be able to access InnerClass so Static would not help I think.  Is it just allowed for simplicity in java
What is the main difference between an inner class and a static nested class in Java? Does design / implementation play a role in choosing one of these?
Algorithms for automatic model selection How can I disable Ctrl+Q for all applications (system wide)? A lot of applications like Firefox, Chrome etc, get closed when I accidentally press Ctrl+Q instead of Ctrl+W because of the proximity of the Q and W keys on the keyboard. Is there a way this shortcut can be removed or reset on a system wide basis? Which folder is recycle bin in on Win7? How to check files there? I was using another account before. Let me call it account A. And I deleted a lot of files to the Recycle Bin at that time. But before I removed account A I forgot to empty the Recycle Bin.   My question is, are my files still there? I've searched and found that the Recycle Bin may live in $Recycle.Bin, but I can't open files there so I can't know what they are. Any help how to open deleted files or how to delete them permanently? How do I color intersection of two ellipses in different color. For instances, the ellipses should themselves be colored as yellow and their intersection as red. My code for drawing ellipses is given below  \draw (-4,0) ellipse (8 and 3); \draw (8,0) ellipse (8 and 3);   UPDATE: In the comments to individual answers, I have requested to show it for three ellipses. Labelled spanning trees of $K_n-e$ Let $e$ be an edge of $K_n$- the complete graph on $n$ vertices. Prove that the number of labelled spanning trees of $K_n-e$ is $(n-2)n^{n-3}$.  I think the answer lies in using some modified form of Prüfer's sequence but I can't quite nail it. Let $f$ be a continuous function on a set $E$.  Is it always true that $f^{-1}(A)$ is always measurable if $A$ is measurable?  I say no.  We know that $\bar{\psi(x)}:=\frac{\phi(x)+x}{2}$ where $\phi$ is the Cantor (or Cantor-Lebesgue) function and $\bar{\psi}:[0,1] \rightarrow [0,1]$.  We know this function maps a measurable subset of $C$ (the Cantor set) into a non-measurable set $W$.  A few observations about $\bar{\psi(x)}$.  It is strictly increasing and continuous, so it has a continuous inverse $\bar{\psi(x)}^{-1}$.  Thus $\bar{\psi(x)}^{-1}(W)=c \subset C$; that is, $\bar{\psi(x)}^{-1}(W)$ is non-measurable, but c is.  Is this correct? Where will changes and fixes to guides and manuals for 5e be found? I'm interested in a grappler build, among others, and don't know where to look to see if the last bullet for the grappler feat has been changed. The grappler example aside, it should be useful to know for future fixes. How is Faulhaber's formula derived? What is a 'multi-part identifier' and why can't it be bound? I continually get these errors when I try to update tables based on another table. I end up rewriting the query, change the order of joins, change some groupings and then it eventually works, but I just don't quite get it.  What is a 'multi-part identifier'? When is a 'multi-part identifier' not able to be bound? What is it being bound to anyway? In what cases will this error occur? What are the best ways to prevent it?    The specific error from SQL Server 2005 is:     The multi-part identifier "..." could not be bound.   Here is an example:  UPDATE  [test].[dbo].[CompanyDetail]  SET Mnemonic = [dbBWKMigration].[dbo].[Company].[MNEMONIC],                 [Company Code] = [dbBWKMigration].[dbo].[Company].[COMPANYCODE]  WHERE [Company Name] = **[dbBWKMigration].[dbo].[Company].[COMPANYNAME]**   The actual error:     Msg 4104, Level 16, State 1, Line 3 The multi-part identifier   "dbBWKMigration.dbo.Company.COMPANYNAME" could not be bound. How do I get the next element in HTML using JavaScript?  Suppose I have three &lt;div&gt;s and I get a reference to one in JavaScript code, I want to get which is the next &lt;div&gt; and which is the previous. I am writing an article in English, with some pages in Russian.  \documentclass[12pt]{article}  \usepackage[T1,T2A]{fontenc}  \usepackage[utf8]{inputenc}  \usepackage[russian,english]{babel}  \usepackage{newtxmath} \usepackage{newtxtext} \begin{document}  hello \textbf{hello}  \selectlanguage{russian} привет \textbf{привет}  \end{document}   Output:  hello hello привет привет  I am using \selectlanguage{} to switch between languages when needed.  However, I noticed that when I try to use \textbf{} when in Russian language mode, it does not work because of newtxtext, which I am using for math formulas.  Does anyone know how to solve this problem?  Thank you. What is a terminal and how do I open and use it? What is a terminal? How do I open a terminal window? How do I use the terminal? What USB drive filesystem works out of the box on Windows, Linux, and OS X? In today's pattern recognition class my professor talked about PCA, eigenvectors and eigenvalues.   I understood the mathematics of it. If I'm asked to find eigenvalues etc. I'll do it correctly like a machine. But I didn't understand it. I didn't get the purpose of it. I didn't get the feel of it.        I strongly believe in the following quote:     You do not really understand something unless you can explain it to your grandmother. -- Albert Einstein   Well, I can't explain these concepts to a layman or grandma.   Why PCA, eigenvectors &amp; eigenvalues? What was the need for these concepts? How would you explain these to a layman? Why (in relatively non-technical terms) are Calabi-Yau manifolds favored for compactified dimensions in string theory? Let $X,Y$ be topological and $f:X \to Y$ be open and continuos.  I am studying Baire space and I would like to try the following facts :      $(i)$ The inverse image of dense set is dense.       $(ii)$ The inverse image of comeager set is comeager.   I am studying Baire space and I would like to try the following facts  Can we collaborate to verify the above claims?    Thanks. What's the difference between absolute path &amp; relative path when using any web server or Tomcat? I'm having trouble understanding how to access each individual result returned from a subquery. The picture shows the code which:   takes fields and objects chosen by a user and assigns them to String variables, the string vars are used to query a dynamic query string, the query string is feed into a database.query and the result is stored in an array I can individually access each of the query results from this array (parent object results),  But I have not been able to individually access the subquery results.   If I feed the subquery results into an array...something like:  SObject[] c = p.get(i).getSObjects(childO);   I still can't get to each individual child record per parent. I can only see all child records per each parent. I need to get to each child record per adult, so that I can roll up results.  Can anyone help?  // These strings will be populated dynamically from a VF page String parentO  = 'Account'; String parentF  = 'Products_Purchased__c'; String childO   = 'Opportunity';     if(childO  == 'Opportunity'){ childO = 'Opportunities'; } String childF   = 'Product_Type__c';  // create dynamic SOQL query string String query = 'SELECT id, (select ' +childF+ ' from ' +childO+') FROM ' +parentO;  // query and store 33 results in variable p SObject[] p = Database.query(query);  for(Integer i = 0; i &lt; p.size(); i++){     system.debug('Parent result from SOQL query: ' +p[i]);     if(p.get(i).getSObjects(childO) &lt;&gt; null){         system.debug('Child result(s) from SOQL query: ' +p.get(i).getSObjects(childO));         system.debug('Child field: ' +c.get(i).get(childF));     } } Deep Format of a Harddrive on a Linux System I've got an original Asus Eee PC Netbook that I'd like to sell.  When I've sold old computers in the past, I've typically done a deep/secure/zeroing out style format.  How can I do this on a Linux Netbook?  I'm looking for   The command that will let me do this Advice on how I can do this on a device with (seemingly?) non-removable media   Thanks in advance! Balloons and lifting gases Hydrogen is the lightest element, so it's cable of lifting the most weight in out atmosphere (probably not the best terminology there, but you get the picture)  Would hot hydrogen (in the same sense as hot air) be able to lift even more mass? Would a higher or lower density of hydrogen in a ballon lift more? If you could have a balloon which had nothing in it (it was a vacuum inside) would that lift more than a hydrogen balloon?  Basically what are the physics to balloons and lifting?  (really not sure what to tag this, so if someone else could that'd be great)