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Retrieve only the queried element in an object array in MongoDB collection
...ction object field name represents the index of the field's first matching array element from the query. The following returns the same results as above:
db.test.find({"shapes.color": "red"}, {_id: 0, 'shapes.$': 1});
MongoDB 3.2 Update
Starting with the 3.2 release, you can use the new $filter...
How do pointer to pointers work in C?
...t address 60.
As to why one uses pointers to pointers:
The name of an array usually yields the address of its first element. So if the array contains elements of type t, a reference to the array has type t *. Now consider an array of arrays of type t: naturally a reference to this 2D array will...
What's the best way to put a c-struct in an NSArray?
What's the usual way to store c-structures in an NSArray ? Advantages, disadvantages, memory handling?
11 Answers
...
Standard alternative to GCC's ##__VA_ARGS__ trick?
... BOOST_PP_GREATER(BOOST_PP_VARIADIC_SIZE(__VA_ARGS__), 1)) \
BOOST_PP_ARRAY_ENUM(BOOST_PP_ARRAY_POP_FRONT( \
BOOST_PP_VARIADIC_TO_ARRAY(__VA_ARGS__)))) \
/**/
Also, why is there no BOOST_PP_ARRAY_ENUM_TRAILING? It would make this solution much less horrible.
Edit: Alright, here ...
Sort Dictionary by keys
...[
"A" : [1, 2],
"Z" : [3, 4],
"D" : [5, 6]
]
let sortedKeys = Array(dictionary.keys).sorted(<) // ["A", "D", "Z"]
EDIT:
The sorted array from the above code contains keys only, while values have to be retrieved from the original dictionary. However, 'Dictionary' is also a 'Collect...
Convert pandas dataframe to NumPy array
I am interested in knowing how to convert a pandas dataframe into a NumPy array.
15 Answers
...
Differences between lodash and underscore [closed]
...Lo-Dash to provide more consistent cross-environment iteration support for arrays, strings, objects, and arguments objects1. It has since become a superset of Underscore, providing more consistent API behavior, more features (like AMD support, deep clone, and deep merge), more thorough documentation...
Get an array of list element contents in jQuery
...are other ways to do the same thing (you could use $.map() to generate the array in one go), but they amount to the same thing.
– Shog9
Nov 1 '13 at 16:01
...
$_POST vs. $_SERVER['REQUEST_METHOD'] == 'POST'
...k the request method — I actually never thought about testing the $_POST array. I check the required post fields, though. So an empty post request would give the user a lot of error messages - which makes sense to me.
shar...
Remove all subviews?
...pment only), you can simply use the following:
[someNSView setSubviews:[NSArray array]];
For UIView (iOS development only), you can safely use makeObjectsPerformSelector: because the subviews property will return a copy of the array of subviews:
[[someUIView subviews]
makeObjectsPerformSelector...