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Why do we need virtual functions in C++?
...rats. Should you overload func() so it takes a Cat*? If you have to derive more animals from Animal they would all need their own func().
The solution is to make eat() from the Animal class a virtual function:
class Animal
{
public:
virtual void eat() { std::cout << "I'm eating g...
Design Patterns: Abstract Factory vs Factory Method
...at are related. It is noticeably different than a Factory Method as it has more than one method of types it produces. (This is complicated refer to next diagram for better real-life example).
Example From The .NET Framework
DbFactoriesProvider is a Simple Factory as it has no sub-types. The DbFa...
Hidden Features of Xcode 4
...t. Xcode 4 now combines these into a single #pragma mark - <name>.
More on pragma mark.
share
edited Feb 23 '12 at 16:58
...
NUnit vs. xUnit
...dely used, well documented and has a large community, whereas xUnit.net is more modern, more TDD adherent, more extensible, and also trending in .NET Core development. It's also well documented.
In addition to that, the main difference I noticed is the way that xUnit.net runs the test methods. So, ...
What's the easiest way to install a missing Perl module?
...ause you specify the distribution that you want to install, which is a lot more honest. For instance, if you use cpan to install LWP, LWP::Simple or LWP::UserAgent it will install the distribution libwww-perl for you. The majority of distributions contain a single module with an equivalent name, but...
Grouping functions (tapply, by, aggregate) and the *apply family
...b c
1 3 91
sapply(x, FUN = sum)
a b c
1 6 5005
In more advanced uses of sapply it will attempt to coerce the
result to a multi-dimensional array, if appropriate. For example, if our function returns vectors of the same length, sapply will use them as columns of a matrix:
sa...
Saving an Object (Data persistence)
...code as in my example -- I purposefully wrote it the way I did to show how more than one object could be saved into (and later read back from) the same file.
– martineau
Dec 25 '10 at 9:57
...
Write lines of text to a file in R
...ike to add lines to the same file? (The issue being is that you can't have more then one connection to a file, If I am not mistaken) Thanks.
– Tal Galili
Mar 18 '10 at 15:02
8
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Why does Twitter Bootstrap Use Pixels for Font Size?
...ully coherent enough. I'll try to blog about these changes as they come up more, but I'm unsure how close 3.0 is and what that will all entail yet.
I would suggest anyone with strong feelings about this go and +1 this thread.
[Update] V3 roadmap oulined in V2.3 release blogpost makes no mention of ...