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How can I return NULL from a generic method in C#?
...(or a nullable value type), 0 for int, '\0' for char, etc. (Default values table (C# Reference))
Restrict T to be a reference type with the where T : class constraint and then return null as normal
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Mapping over values in a python dictionary
..., f(kv[1])), my_dictionary.iteritems()))
but that's not that readable, really.
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Python list subtraction operation
... [1,2] you will get empty list. [1,1,2,2] - [2] gives [1,1] So it is not really list substraction, it is more like "List from List X without elements from set Y".
– Alfred Zien
Feb 6 '16 at 10:25
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Synchronous request in Node.js
If I need to call 3 http API in sequential order, what would be a better alternative to the following code:
18 Answers
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PHP array_filter with arguments
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As an alternative to @Charles's solution using closures, you can actually find an example in the comments on the documentation page. The idea is that you create an object with the desired state ($num) and the callback method (taking $i as an argument):
class LowerThanFilter {
private ...
How do I test an AngularJS service with Jasmine?
... problem is that the factory method, that instantiate the service, is not called in the example above (only creating the module doesn't instantiate the service).
In order to the service to be instantiated angular.injector has to be called with the module where our service is defined. Then, we can a...
How to use the PI constant in C++
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On some (especially older) platforms (see the comments below) you might need to
#define _USE_MATH_DEFINES
and then include the necessary header file:
#include <math.h>
and the value of pi can be accessed via:
M_PI
In my math....
What's the difference between lists and tuples?
.... A list on the other hand could be used to store multiple locations. Naturally one might want to add or remove locations from the list, so it makes sense that lists are mutable. On the other hand it doesn't make sense to add or remove items from an existing location - hence tuples are immutable.
T...
In PHP with PDO, how to check the final SQL parametrized query? [duplicate]
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SET GLOBAL log_output = 'TABLE'; SELECT * FROM mysql.general_log;
– Tyler Miles
Oct 21 '18 at 2:27
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Calling C/C++ from Python?
...e Boost Python Library is a framework for interfacing Python and
C++. It allows you to quickly and seamlessly expose C++ classes
functions and objects to Python, and vice-versa, using no special
tools -- just your C++ compiler. It is designed to wrap C++ interfaces
non-intrusively, so that y...