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Remove empty elements from an array in Javascript
...ll return you a new array with the elements that pass the criteria of the callback function you provide to it.
For example, if you want to remove null or undefined values:
var array = [0, 1, null, 2, "", 3, undefined, 3,,,,,, 4,, 4,, 5,, 6,,,,];
var filtered = array.filter(function (el) {
...
java: HashMap not working
...ittle difference in the code. Auto-boxing means you can write:
myMap.put("foo", 3);
instead of:
myMap.put("foo", new Integer(3));
Auto-boxing means the first version is implicitly converted to the second. Auto-unboxing means you can write:
int i = myMap.get("foo");
instead of:
int i = myMa...
Using reflect, how do you set the value of a struct field?
...rue if the value's
address can be obtained with Addr.
Such values are called addressable. A
value is addressable if it is an
element of a slice, an element of an
addressable array, a field of an
addressable struct, or the result of
dereferencing a pointer. If CanAddr
returns false, c...
How to delete a file or folder?
...mdir() removes an empty directory.
shutil.rmtree() deletes a directory and all its contents.
Path objects from the Python 3.4+ pathlib module also expose these instance methods:
pathlib.Path.unlink() removes a file or symbolic link.
pathlib.Path.rmdir() removes an empty directory.
...
OS X Bash, 'watch' command
...expand parameters before running the script, so in a directory with files "foo" and "bar", you'd run cat foo bar every 2 seconds. What behaviour were you expecting?
– ghoti
Aug 19 '13 at 14:33
...
Which way is best for creating an object in JavaScript? Is `var` necessary before an object property
...your example, Person (you should start the name with a capital letter) is called the constructor function. This is similar to classes in other OO languages.
Use way 2 if you only need one object of a kind (like a singleton). If you want this object to inherit from another one, then you have to use a...
How do I write a short literal in C++?
...rt enough to compile this as if it's a short literal (i.e. it wouldn't actually allocate an int and then cast it every time).
The following illustrates how much you should worry about this:
a = 2L;
b = 2.0;
c = (short)2;
d = '\2';
Compile -> disassemble ->
movl $2, _a
movl $2, _b
m...
What's Mongoose error Cast to ObjectId failed for value XXX at path “_id”?
...that it can properly query for the matching doc. This is an ObjectId but "foo" is not a valid ObjectId so the cast fails.
This doesn't happen with 41224d776a326fb40f000001 because that string is a valid ObjectId.
One way to resolve this is to add a check prior to your findById call to see if id i...
Does C++ support 'finally' blocks? (And what's this 'RAII' I keep hearing about?)
Does C++ support ' finally ' blocks?
16 Answers
16
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What does the [Flags] Enum Attribute mean in C#?
... Such collections are often used with bitwise operators, for example:
var allowedColors = MyColor.Red | MyColor.Green | MyColor.Blue;
Note that the [Flags] attribute doesn't enable this by itself - all it does is allow a nice representation by the .ToString() method:
enum Suits { Spades = 1, Clu...