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How can I add new keys to a dictionary?
...y by assigning a value
to that key. If the key doesn't exist, it's added and points to that
value. If it exists, the current value it points to is overwritten.
—R. Navega
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Static Initialization Blocks
...the constructor's job to initialize fields.
– Martin Andersson
Apr 1 '13 at 18:56
2
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How to specialize std::hash::operator() for user-defined type in unordered containers?
To support user-defined key types in std::unordered_set<Key> and std::unordered_map<Key, Value>
one has to provide operator==(Key, Key) and a hash functor:
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MySQL “WITH” clause
...RDBMS products that support common table expressions:
Oracle 9i release 2 and later:
http://www.oracle-base.com/articles/misc/with-clause.php
Microsoft SQL Server 2005 and later:
http://msdn.microsoft.com/en-us/library/ms190766(v=sql.90).aspx
IBM DB2 UDB 8 and later:
http://publib.boulder.ibm.com/i...
How to validate an email address in JavaScript
... for "RFC822" or "RFC2822" to get a proper regex.
– Randal Schwartz
Sep 8 '10 at 2:34
45
This doe...
In Hibernate Validator 4.1+, what is the difference between @NotNull, @NotEmpty, and @NotBlank?
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@NotEmpty: The CharSequence, Collection, Map or Array object is not null and size > 0.
@NotBlank: The string is not null and the trimmed length is greater than zero.
To help you understand, let's look into how these constraints are defined and carried out (I'm using version 4.1):
The @Not...
Logical XOR operator in C++?
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Note that this only works for booleans. And ^ would work perfectly well there. 2 !=1 => 1 which is not what you want! as LiraNuna says, putting a ! infront of both sides solves that problem. but again, then you can use bitwise ^...
– Brian...
Ignore mouse interaction on overlay image
I have a menu bar with hover effects, and now I want to place a transparent image with a circle and a "handdrawn" text over one of the menu items. If I use absolute positioning to place the overlay image above the menu item, the user will not be able to click the button and the hover effect will not...
Bootstrap trying to load map file. How to disable it? Do I need to do it?
I'm recently playing with bootsrap3. I compiled it from sources and included distr js and css to my project. The thing is, I see in GH dev tools, that it's trying to get .map.css file. Why does it want to do so? How to disable it? Do I need to disable it? To not to have an error mark in dev tools, I...
What is an example of the simplest possible Socket.io example?
So, I have been trying to understand Socket.io lately, but I am not a supergreat programmer, and almost every example I can find on the web (believe me I have looked for hours and hours), has extra stuff that complicates things. A lot of the examples do a bunch of things that confuse me, or connect ...