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Why rename synthesized properties in iOS with leading underscores? [duplicate]
...project in Xcode 4, the boilerplate code adds an underscore character when it synthesizes the ivars in the implementation file as:
...
What HTTP status response code should I use if the request is missing a required parameter?
I am thinking 412 (Precondition Failed) but there may be a better standard?
12 Answers
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Python nonlocal statement
...
Compare this, without using nonlocal:
x = 0
def outer():
x = 1
def inner():
x = 2
print("inner:", x)
inner()
print("outer:", x)
outer()
print("global:", x)
# inner: 2
# outer: 1
# global: 0
To this, usi...
Sync data between Android App and webserver [closed]
...ice.
Persistent Storage:
This is how your phone actually stores the data it receives from the webserver. One possible method for accomplishing this is writing your own custom ContentProvider backed by a Sqlite database. A decent tutorial for a content provider can be found here: http://thinkandroi...
Can You Get A Users Local LAN IP Address Via JavaScript?
I know the initial reaction to this question is "no" and "it can't be done" and "you shouldn't need it, you are doing something wrong". What I'm trying to do is get the users LAN IP address, and display it on the web page. Why? Because that's what the page I'm working on is all about, showing as muc...
Reading output of a command into an array in Bash
...characters like *, ?, [...].
To get the output of a command in an array, with one line per element, there are essentially 3 ways:
With Bash≥4 use mapfile—it's the most efficient:
mapfile -t my_array < <( my_command )
Otherwise, a loop reading the output (slower, but safe):
my_array=(...
MySQL order by before group by
...ou have the following sample data:
CREATE TABLE wp_posts
(`id` int, `title` varchar(6), `post_date` datetime, `post_author` varchar(3))
;
INSERT INTO wp_posts
(`id`, `title`, `post_date`, `post_author`)
VALUES
(1, 'Title1', '2013-01-01 00:00:00', 'Jim'),
(2, 'Title2', '2013-02-01 0...
How can I create directory tree in C++/Linux?
...
With C++17 or later, there's the standard header <filesystem> with
function
std::filesystem::create_directories
which should be used in modern C++ programs.
The C++ standard functions do not have the POSIX-specific expli...
In Javascript/jQuery what does (e) mean?
...e been learning how to make functions. A lot of functions have cropped up with (e) in brackets. Let me show you what I mean:
...
What's faster, SELECT DISTINCT or GROUP BY in MySQL?
...e databases implement DISTINCT under the hood).
If one of them is faster, it's going to be DISTINCT. This is because, although the two are the same, a query optimizer would have to catch the fact that your GROUP BY is not taking advantage of any group members, just their keys. DISTINCT makes this ...