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How to convert a string or integer to binary in Ruby?
...
You would naturally use Integer#to_s(2), String#to_i(2) or "%b" in a real program, but, if you're interested in how the translation works, this method calculates the binary representation of a given integer using basic operators:
def int_t...
How to restore to a different database in sql server?
...mpCopy with the contents of your.bak.
Example (restores a backup of a db called 'creditline' to 'MyTempCopy';
RESTORE FILELISTONLY FROM DISK='e:\mssql\backup\creditline.bak'
>LogicalName
>--------------
>CreditLine
>CreditLine_log
RESTORE DATABASE MyTempCopy FROM DISK='e:\mssql\backu...
Send and receive messages through NSNotificationCenter in Objective-C?
...
@implementation TestClass
- (void) dealloc
{
// If you don't remove yourself as an observer, the Notification Center
// will continue to try and send notification objects to the deallocated
// object.
[[NSNotificationCenter defaultCenter] removeO...
How to delete migration files in Rails 3
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I usually:
Perform a rake db:migrate VERSION=XXX on all environments, to the version before the one I want to delete.
Delete the migration file manually.
If there are pending migrations (i.e., the migration I removed was not the...
what is reverse() in Django
...!-- django <= 1.4 -->
<a href="{% url url_name %}">link which calls some_view</a>
<!-- django >= 1.5 or with {% load url from future %} in your template -->
<a href="{% url 'url_name' %}">link which calls some_view</a>
This will be rendered as:
<a href="...
How to get a Docker container's IP address from the host
...n. Maybe provide two examples clearly labelled Linux and Windows. I literally just typed the example, checked the docs which also uses single quotes and then Googled the error. I'm sure I'm not alone.
– Wyck
Apr 15 '19 at 18:42
...
PHP session lost after redirect
...
First, carry out these usual checks:
Make sure session_start(); is called before any sessions are being called. So a safe bet would be to put it at the beginning of your page, immediately after the opening <?php declaration before anything else. Also ensure there are no whitespaces/tabs be...
Property getters and setters
...g to backup the computed property. Try this:
class Point {
private var _x: Int = 0 // _x -> backingX
var x: Int {
set { _x = 2 * newValue }
get { return _x / 2 }
}
}
Specifically, in the Swift REPL:
15> var pt = Point()
pt: Point = {
_x = 0
}
16> pt.x = 10...
Why do we need message brokers like RabbitMQ over a database like PostgreSQL?
...ustering options are also available.
In regards to AMQP, I would say a really cool feature is the "exchange", and the ability for it to route to other exchanges. This gives you more flexibility and enables you to create a wide array of elaborate routing typologies which can come in very handy when...
find() with nil when there are no records
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Yes, just do:
Challenge.find_by_id(10)
For Rails 4 and 5:
Challenge.find_by(id: 10)
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