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How can I check whether a option already exist in select by JQuery
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This evaluates to true if it already exists:
$("#yourSelect option[value='yourValue']").length > 0;
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GitHub: make fork an “own project”
...emented are not in the vision of the original author and we simply aim at different goals. I don't know as I never got responses from him.
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Divide a number by 3 without using *, /, +, -, % operators
...gt;> 2, sum);
num = add(num >> 2, num & 3);
}
if (num == 3)
sum = add(sum, 1);
return sum;
}
As Jim commented this works, because:
n = 4 * a + b
n / 3 = a + (a + b) / 3
So sum += a, n = a + b, and iterate
When a == 0 (n < 4), sum += floor(n / 3); i....
How do I use NSTimer?
...led "Companion Guides", which lists guides for the topic being documented (if any exist). For example, with NSTimer, the documentation lists two companion guides:
Timer Programming Topics for Cocoa
Threading Programming Guide
For your situation, the Timer Programming Topics article is likely to ...
Find first element in a sequence that matches a predicate
...t element in a sequence seq that matches a predicate:
next(x for x in seq if predicate(x))
Or (itertools.ifilter on Python 2):
next(filter(predicate, seq))
It raises StopIteration if there is none.
To return None if there is no such element:
next((x for x in seq if predicate(x)), None)
O...
Access-Control-Allow-Origin Multiple Origin Domains?
...e client, compare that to the list of domains you would like to allow, and if it matches, echo the value of the Origin header back to the client as the Access-Control-Allow-Origin header in the response.
With .htaccess you can do it like this:
# ----------------------------------------------------...
Best way to load module/class from lib folder in Rails 3?
...ls 2.3.9, there is a setting in config/application.rb in which you can specify directories that contain files you want autoloaded.
From application.rb:
# Custom directories with classes and modules you want to be autoloadable.
# config.autoload_paths += %W(#{config.root}/extras)
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In Python, when to use a Dictionary, List or Set?
...ct and set don't: when you care about order, therefore, you must use list (if your choice of containers is limited to these three, of course;-).
dict associates with each key a value, while list and set just contain values: very different use cases, obviously.
set requires items to be hashable, li...
How do I use the nohup command without getting nohup.out?
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The nohup command only writes to nohup.out if the output would otherwise go to the terminal. If you have redirected the output of the command somewhere else - including /dev/null - that's where it goes instead.
nohup command >/dev/null 2>&1 # doesn't cre...
RegEx match open tags except XHTML self-contained tags
...he same conceptual space will destroy your mind like so much watery putty. If you parse HTML with regex you are giving in to Them and their blasphemous ways which doom us all to inhuman toil for the One whose Name cannot be expressed in the Basic Multilingual Plane, he comes. HTML-plus-regexp will l...