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How do I concatenate strings and variables in PowerShell?
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This isn't technically concatenation.
– TravisEz13
Jun 14 '16 at 17:59
9
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What is the copy-and-swap idiom?
...s arguably the most nuanced and difficult. How should it be done? What pitfalls need to be avoided?
The copy-and-swap idiom is the solution, and elegantly assists the assignment operator in achieving two things: avoiding code duplication, and providing a strong exception guarantee.
How does it wor...
In Python, how can you load YAML mappings as OrderedDicts?
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Update: In python 3.6+ you probably don't need OrderedDict at all due to the new dict implementation that has been in use in pypy for some time (although considered CPython implementation detail for now).
Update: In python 3.7+, the insertion-order preservation nature of dict objects h...
Immutability of Strings in Java
...t, and changing a reference. s2 still points to the same object as we initially set s1 to point to. Setting s1 to "Help!" only changes the reference, while the String object it originally referred to remains unchanged.
If strings were mutable, we could do something like this:
String s1 = "Hello";
St...
Quickest way to convert a base 10 number to any base in .NET?
...comments, Convert.ToString only supports the following limited - but typically sufficient - set of bases: 2, 8, 10, or 16.
Update (to meet the requirement to convert to any base):
I'm not aware of any method in the BCL which is capable to convert numbers to any base so you would have to write you...
What does new self(); mean in PHP?
... the parent class
The first situation would look like this (I've removed all non-necessary code, for this example -- you'll have to add it back to get the singleton behavior)* :
class MyParentClass {
}
class MyChildClass extends MyParentClass {
public static function getInstance() {
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In Django, how do I check if a user is in a certain group?
...add(group) # user is now in the "Editor" group
then user.groups.all() returns [<Group: Editor>].
Alternatively, and more directly, you can check if a a user is in a group by:
if django_user.groups.filter(name = groupname).exists():
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Note that groupname can also be the ac...
Open link in new tab or window [duplicate]
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It shouldn't be your call to decide whether the link should open in a new tab or a new window, since ultimately this choice should be done by the settings of the user's browser. Some people like tabs; some like new windows.
Using _blank will tell...
Why do you need explicitly have the “self” argument in a Python method?
... to make things like this explicit rather than based on a rule.
Additionally, since nothing is implied or assumed, parts of the implementation are exposed. self.__class__, self.__dict__ and other "internal" structures are available in an obvious way.
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Get notified when UITableView has finished asking for data?
...eload its data. So, when the second NSLog is fired, the table view has actually finish asking for data.
I've subclassed UITableView to send methods to the delegate before and after reloadData. It works like a charm.
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