NullPointerException in reading data from sqlite
What is a NullPointerException, and how do I fix it?
Countinuity of the identity map between different topologies Why do we use "dried up" instead of just "dried"? The creek has dried up.   In this example sentence, you should say "dried up." If you say just "dried," it sounds incomplete. Is this an example of an idiom or is there a grammatical rule governing this instance? If so, what is it? I just learned about the C++ construct called "placement new".  It allows you to exactly control where a pointer points to in memory.  It looks like this:   #include &lt;new&gt;        // Must #include this to use "placement new"  #include "Fred.h"     // Declaration of class Fred   void someCode()  {    char memory[sizeof(Fred)];    void* place = memory;     Fred* f = new(place) Fred();   // Create a pointer to a Fred(),                                   // stored at "place"     // The pointers f and place will be equal     ...  }    (example from ) In this example, the this pointer of Fred will be equal to place.    I've seen it used in our team's code once or twice.  In your experience, what does this construct enable?  Do other pointer languages have similar constructs?  To me, it seems reminiscent of equivalence in FORTRAN, which allows disparate variables to occupy the same location in memory. Which are the spec bits in this cache? I have a direct mapped cache of size S with the line size L. The cache is physically indexed and tagged. The physical address is 50 bits, numbered from 0 to 49 (with 0 being the least significant bit). The machine has a word size of 4 bits and the memory is byte-addressable. Which bits of the 50 bits are compared with the address tag? Trying to open a http website on any web browser (event telnet) gives a ‘ERR_CONNECTION_REFUSED’ or ‘connection timed out’.  However, the same sites can be opened using https. I tried doing a traceroute and it works fine.  I am new to OS X but have experience with Linux. How do I go about troubleshooting this issue?  Update  I think I've tracked down the culprit to a rule in pf (firewall).  The result of sudo pfctl -s nat is:  No ALTQ support in kernel ALTQ related functions disabled rdr pass inet proto tcp from 192.168.0.101 to any port = 80 -&gt; 127.0.0.1 port 9882   192.168.0.101 is the current ip address of the computer.  I tried to remove the rule with sudo pfctl -F all, but it is back after a few seconds. I didn't find the rule in the default configurations (/etc/pf.conf). And disabling pf with sudo pfctl -d has no effect on it.  Is this a malware issue? Confused about the possibility of different differentiable structures. In Loring Tu's "An Introduction to Manifolds" an atlas on a manifold is a collection of coordinate charts that are pairwise compatible and cover the manifold. A smooth manifold is defined to be a topological manifold together with a maximal atlas or differentiable structure. The maximal atlas is constructed by taking an atlas and appending all coordinate charts that are compatible with the atlas and using this he shows that any atlas on a locally Euclidean space is contained in a unique maximal atlas.  He also later shows that for any chart on a manifold, the coordinate map is a diffeomorphism onto it's image.   My question arises when Tu mentions in an aside that every compact topological manifold in dimension four or higher has a finite number of differentiable structures. What I don't understand is how it is possible for a smooth manifold to have more than one differentiable structure. Doesn't the fact that for any chart the coordinate map being a diffeomorphism coupled with the fact that composition of smooth functions is smooth mean that any two coordinate charts on a manifold are compatible and thus they must all belong to one maximal atlas? How is it possible to have another? Am I not understanding the word "maximal" or atlas or some other concept? I've searched websites, written to Mr. Barth and William Safire, scanned bookstore shelves, and buttonholed likely prospects in search of a grammar text that would address matters in the manner of the following, which is from John Barth's "The End of the Road".  If such a text exists, I'd be much obliged to learn of it:  " ... it gives a man a great sense of lucidity and well-being, if not downright formidability, to be able not only to say, but to understand perfectly, that predicate complements of infinitives of copulative verbs without expressed subjects go into the nominative case, whereas predicate complements of infinitives of copulative verbs with expressed subjects go into the objective case.  I made this observation to my assemblage of young scholars and concluded triumphantly, "I was thought to be he, but I thought John to be him."  Thank you. Automatically put PGFPlots xtick scale label in x axis label Do you need to erase the memory of *watching* a memory in a Pensieve? How to import a jar in Eclipse No Drupal Site Found when clearing cache I installed drush using composer following the instructions here:   When trying to run drush cc all I get this error:     No Drupal site found, only 'drush' cache was cleared.[warning] 'all'   cache was cleared. [success]   I added this line:  export PATH="/Applications/MAMP/bin/php/php5.6.2/bin:$PATH"   to my .bash_profile and restarted bash and MAMP. Still no luck. Any ideas?   This is my drush status:   Drupal version         :  7.36                                                               Site URI               :  http://default                                                     Database driver        :  mysql                                                              Database hostname      :  localhost                                                          Database port          :                                                                     Database username      :  root                                                               Database name          :  srod                                                     PHP executable         :  /usr/bin/php                                                       PHP configuration      :                                                                     PHP OS                 :  Darwin                                                             Drush script           :  /Users/srod/.composer/vendor/drush/drush/drush.php   Drush version          :  7.0-dev                                                            Drush temp directory   :  /tmp                                                               Drush configuration    :                                                                     Drush alias files      :                                                                     Drupal root            :  /Applications/MAMP/htdocs/srodsite                             Site path              :  sites/default      I'm running it from Drupal project folder. Do lightsabers have safety settings? While rewatching Star Wars my skin was crawling while watching Luke practice saber technique against a remote on the Falcon.  There's no way I'd want to be in the same room with a beginner waving a lightsaber around, let alone a beginner with his eyes covered.  Samurai apparently practiced with  to reduce training injuries.  Do lightsabers have lower power settings so that a wrong move while practicing doesn't sever a limb or chop through the hull into vacuum? Suppose I have a python object x and a string s, how do I set the attribute s on x? So:  &gt;&gt;&gt; x = SomeObject() &gt;&gt;&gt; attr = 'myAttr' &gt;&gt;&gt; # magic goes here &gt;&gt;&gt; x.myAttr 'magic'   What's the magic? The goal of this, incidentally, is to cache calls to x.__getattr__(). Get a generic method without using GetMethods I want to get the method System.Linq.Queryable.OrderyBy&lt;T, TKey&gt;(the IQueryable&lt;T&gt; source, Expression&lt;Func&lt;T,TKey&gt;&gt; keySelector) method, but I keep coming up with nulls.  var type = typeof(T); var propertyInfo = type.GetProperty(group.PropertyName); var propertyType = propertyInfo.PropertyType;  var sorterType = typeof(Func&lt;,&gt;).MakeGenericType(type, propertyType); var expressionType = typeof(Expression&lt;&gt;).MakeGenericType(sorterType);  var queryType = typeof(IQueryable&lt;T&gt;);  var orderBy = typeof(System.Linq.Queryable).GetMethod("OrderBy", new[] { queryType, expressionType }); /// is always null.   Does anyone have any insight? I would prefer to not loop through the GetMethods result. I'm wondering why WordPress does not support sessions and many people out there claim that putting the following code in functions.php might not be a good idea (it in fact works for me but returns PHP warnings, too):  function cp_admin_init() { if (!session_id()) session_start(); }  add_action(‘init’, ‘cp_admin_init’);   Is it good idea to enable sessions in WordPress? What would be the correct way to do this? How can I stop iPhone prompting me to setup Apple Pay in Settings? My son is almost 3 (33 months) and for the past few months, he has been holding his poop in, to the point that he won't go for many days a time. When this started, the doctor advised us to give him Miralax to make his stool softer so it comes out more easily. Even with the Miralax, he still managed to hold it for two days at a time sometimes, but at least it was coming out at all, so we continued with it.  Anyway, we've been giving him the Miralax for months now, and now he's (supposed to be) going to preschool in September, which of course requires that he be potty trained. We don't want to hold him back since he's developmentally ready otherwise, so we started potty training a few weeks ago.  He picked up the potty training really quickly – for peeing – but he still holds his poop in no matter what. If he's sitting on the potty, as soon as he's about to do it, he stands up and just keeps holding it in (and once he starts to stand, if we even so much as ask him to sit back down, he screams and cries).  We have tried everything to convince him (or distract him enough) to sit and poop: reading books, singing songs, playing games, playing with toys, offering him snacks/treats (graham crackers), giving him stickers, etc. Nothing works.  As of today, it has been a week since the last time he pooped, with the exception of a little bit today and a little bit yesterday (both of which ended up all over the bathroom floor since he won't sit down). The doctor says now we should give him an enema to force it all to come out, but even so, that won't solve anything going forward since he still won't go in his diaper or on the potty in the first place (what are we going to do, give him an enema every week, indefinitely?).  The issue isn't that he's scared of the potty itself, since (a) he was holding it before we started potty training, and (b) he knows exactly what he's supposed to do, since he has no problem with peeing (he sits down himself, points it out afterward, knows that it gets emptied into the big potty, etc.).  It's that he just won't poop, ever – not in his diaper, not on the potty – and the only reason why anything comes out at all is because we've been giving him the Miralax every day (and even then, these aren't "full" poops, just whatever happens to come out because it's soft enough that he's unable to hold it all in).  I'm at a complete loss as to why this even started, and what if anything we can do that would actually help. Is it a behavioral problem? Medical? Both?? Help!    UPDATE: I just wanted to update this question since a lot has changed since I originally posted it. We discovered there was a specific situation where he would go in his diaper voluntarily: in our bedroom closet with the door closed. So we knew then that the withholding was intentional, since it was now established that he could go if he wanted to.  So we let him continue going in the closet and, over time, found that he usually went around the same time each day. Based on that, we then had him sit on the potty when we knew it was most likely he would need to go. We also managed to find two things that distracted him enough to sit (blowing bubbles and playing with his toy laptop).  By doing this, we were able to get him to go on the potty without really realizing it (so he didn't try to fight it), and then made a big deal out of it every time he did. Over time, that helped establish that that's what he was supposed to do, and now he does so voluntarily. He hasn't pooped in his diaper in probably 3 weeks by now.  I wouldn't say he's "fully" potty trained, in that an adult still needs to go with him and distract him (and occasionally remind him when he needs to go in general), but finally we made progress. Exclusion in formation of comparative statements I was going through the topic "formation of comparative and superlative".       The rule says     When two objects are compared with each other, the latter term of comparison must exclude the former, as in "Iron is more useful than any other metal". If we say "Iron is more useful than any metal", that is the same thing as saying    "Iron is more useful than iron", since iron is itself a metal.   I am finding difficulty to relate the rule with example. What's the limit of the sequence $\lim\limits_{n \to\infty} \frac{n!}{n^n}$? What is the physical meaning of $\epsilon_0$?