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@OneToMany List vs Set difference
...of addresses, you won't be able to use a single query to load persons with all their contacts and all their addresses. The solution in this case is to make two queries (which avoids the cartesian product), or to use a Set instead of a List for at least one of the collections.
It's often hard to use...
Assign same value to multiple variables at once?
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@Eoin: In doing $var_a = $var_b = ... = new Class();, all the variables will reference the same instance of Class.
– Tim Cooper
Jun 21 '19 at 19:34
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Why don't Java Generics support primitive types?
...nerics in Java are an entirely compile-time construct - the compiler turns all generic uses into casts to the right type. This is to maintain backwards compatibility with previous JVM runtimes.
This:
List<ClassA> list = new ArrayList<ClassA>();
list.add(new ClassA());
ClassA a = list.g...
Why is “if not someobj:” better than “if someobj == None:” in Python?
...a __nonzero__ special method (as do numeric built-ins, int and float), it calls this method. It must either return a bool value which is then directly used, or an int value that is considered False if equal to zero.
Otherwise, if the object has a __len__ special method (as do container built-ins, li...
Meaning of Git checkout double dashes
...maybe 20 or so), most commands are separate programs from Bash. It is actually part of the POSIX standard that -- can be used to separate options from other arguments, so you will see it on commands like cp and mv (which are not part of Bash).
– Dietrich Epp
N...
What is Microsoft.csharp.dll in .NET 4.0
... The assembly contains the C# runtime binder.
The C# compiler has essentially been extracted out into a library so that it can emit, compile and run code needed to support the dynamic keyword. The first time you use dynamic in your code, this assembly (as well as System.dll, System.Core.dll and Sy...
if A vs if A is not None:
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The statement
if A:
will call A.__nonzero__() (see Special method names documentation) and use the return value of that function. Here's the summary:
object.__nonzero__(self)
Called to implement truth value testing and the built-in operation ...
“int main (vooid)”? How does that work?
I recently had to type in a small C test program and, in the process, I made a spelling mistake in the main function by accidentally using vooid instead of void .
...
npm command to uninstall or prune unused packages in Node.js
Is there a way to simply uninstall all unused (undeclared) dependencies from a Node.js project (ones that are no longer defined in my package.json .) When I update my application I like to have the unreferenced packages removed automatically.
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Significance of a .inl file in C++
...st example is the STL header files which have no extension whatsoever.
Usually, ".inl" files do contain inline code (hence the ".inl" extension).
Those files ".inl" files are a necessity when you have a dependency cycle between header code.
For example:
// A.hpp
struct A
{
void doSomethingEl...