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When to use os.name, sys.platform, or platform.system?
...specific modules are available (e.g. posix, nt, ...)
platform.system() actually runs uname and potentially several other functions to determine the system type at run time.
My suggestion:
Use os.name to check whether it's a posix-compliant system.
Use sys.platform to check whether it's a linux,...
jQuery: checking if the value of a field is null (empty)
...ype]').val().length != 0){}
If you want to check if the element exist at all, you should do that before calling val:
var $d = $('#person_data[document_type]');
if ($d.length != 0) {
if ($d.val().length != 0 ) {...}
}
s...
In c++ what does a tilde “~” before a function name signify?
... memory, etc. etc.
Here's a description from ibm.com:
Destructors are usually used to deallocate memory and do other cleanup for a class object and its class members when the object is destroyed. A destructor is called for a class object when that object passes out of scope or is explicitly delete...
How to write multiple line string using Bash with variables?
How can I write multi-lines in a file called myconfig.conf using BASH?
6 Answers
6
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Replace selector images programmatically
...that has a drawable image resource set to a selector. How do I programmatically access the selector and change the images of the highlighted and non-highlighted state?
...
No secret option provided to Rack::Session::Cookie warning?
...
Update your rails gems as this is backported to all supported rails gems. note @henrik-n
– shadowbq
Feb 4 '13 at 11:14
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What is the difference between `after_create` and `after_save` and when to use which?
... readers should note that, according to the docs, ActiveRecord's update_all does not invoke any callbacks, including after_*
– user2426679
Jan 10 at 19:34
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GLib compile error (ffi.h), but libffi is installed
...
If you have a Debian-based Linux OS with apt-get:
sudo apt-get install libffi-dev
With a Redhat-base OS:
yum install libffi-devel
With Alpine Linux:
apk add libffi-dev
share
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improve...
Join strings with a delimiter only if strings are not null or empty
...
.filter(Boolean) (which is the same as .filter(x => x)) removes all "falsy" values (nulls, undefineds, empty strings etc). If your definition of "empty" is different, then you'll have to provide it, for example:
[...].filter(x => typeof x === 'string' && x.length > 0)
wi...
Haskell composition (.) vs F#'s pipe forward operator (|>)
...s pipelining, so that a known type appears on the left (see here).
(Personally, I find points-free style unreadable, but I suppose every new/different thing seems unreadable until you become accustomed to it.)
I think both are potentially viable in either language, and history/culture/accident may...