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When should I use the Visitor Design Pattern? [closed]
...
(Suppose it is a complex hierarchy with a well-established interface.)
Now we want to add a new operation to the hierarchy, namely we want each animal to make its sound. As far as the hierarchy is this simple, you can do it with straight polymorphism:
class Animal
{ public: virtual void makeSou...
How to find day of week in php in a specific timezone
... Europe/Stockholm to the users time-zone.
$dateTime = new \DateTime(
'now',
new \DateTimeZone('Europe/Stockholm')
);
$day = $dateTime->format('N');
ISO-8601 numeric representation of the day of the week (added in PHP 5.1.0)
1 (for Monday) through 7 (for Sunday)
http://php.net/ma...
What are sessions? How do they work?
... to store that data server side, give it an "id", and let the client only know (and pass back at every http request) that id. There you go, sessions implemented. Or you can use the client as a convenient remote storage, but you would encrypt the data and keep the secret server-side.
Of course there...
Failed to allocate memory: 8
... amount of ram I had specified for the virtual machine, and it was 1024MB, now I have 512MB and it is ok, now I need to find how to improve this amount of ram, 512 is not so much, and the machine is a little bit laggy.
share...
How do I update a GitHub forked repository?
...itHub. When you create a forked repository on GitHub and clone it, GitHub knows that the repository is a fork; Git has no reason to, and does not. (Why doesn't the clone copy the Git remotes? Git is decentralized; different people will want different remotes; it would make no sense to do this.) See ...
Random data in Unit Tests?
... counter-evidence to refute that the program works according to the spec.
Now, you can write the unit tests by hand, but it really is a mechanical task. It can be automated. All you have to do is write the spec, and a machine can generate lots and lots of unit tests that try to break your code.
I ...
Determine what attributes were changed in Rails after_save callback?
...
I think after_update is deprecated now? Anyway, I tried this in an after_save hook and that seemed to work fine. (The changes() hash still hasn't been reset yet in an after_save, apparently.)
– Tyler Rick
Mar 14 '13 at 5:...
How does data binding work in AngularJS?
... to one or the other, but each time you add you fire a change event, which now has an inconsistent view of the world. This is a very similar problem to thread locking, which JavaScript avoids since each callback executes exclusively and to completion. Change events break this since setters can have ...
PHP/MySQL insert row then get 'id'
...
As to PHP's website, mysql_insert_id is now deprecated and we must use PDO. To do this with PDO, proceed as following:
$db = new PDO('mysql:dbname=database;host=localhost', 'user', 'pass');
$statement = $db->prepare('INSERT INTO people(name, city) VALUES(:name,...
GitHub: How to make a fork of public repository private?
...Creates a merge commit
git push origin master
Awesome, your private repo now has the latest code from the public repo plus your changes.
Finally, to create a pull request private repo -> public repo:
Use the GitHub UI to create a fork of the public repo (the small "Fork" button at the top r...