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Why covariance and contravariance do not support value type
...or not.
You might want to read Eric Lippert's blog post on representation and identity for more on this topic in general.
EDIT: Having reread Eric's blog post myself, it's at least as much about identity as representation, although the two are linked. In particular:
This is why covariant and ...
How do you detect Credit card type based on number?
...gy in some documents). These six digits are subject to an international standard, ISO/IEC 7812, and can be used to determine the type of card from the number.
Unfortunately the actual ISO/IEC 7812 database is not publicly available, however, there are unofficial lists, both commercial and free, in...
Difference between HEAD and master
What is the difference between the HEAD and master in Git?
3 Answers
3
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Round a Floating Point Number Down to the Nearest Integer?
As the title suggests, I want to take a floating point number and round it down to the nearest integer. However, if it's not a whole, I ALWAYS want to round down the variable, regardless of how close it is to the next integer up. Is there a way to do this?
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Split a String into an array in Swift?
... that String no longer adopts the SequenceType or CollectionType protocols and you must instead use the .characters property to access a CharacterView type representation of a String instance. (Note: CharacterView does adopt SequenceType and CollectionType protocols).
let fullName = "First Last"
le...
How to get existing fragments when using FragmentPagerAdapter
...entPagerAdapter , as a helper class that implements the management of tabs and all details of connecting a ViewPager with associated TabHost . I have implemented FragmentPagerAdapter just as same as it is provided by the Android sample project Support4Demos .
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Use find command but exclude files in two directories
...t to find files that end with _peaks.bed , but exclude files in the tmp and scripts folders.
6 Answers
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Deleting an element from an array in PHP
...n use unset() or alternatively \array_splice().
Also if you have the value and don't know the key to delete the element you can use \array_search() to get the key.
unset()
Note that when you use unset() the array keys won't change/reindex. If you want to reindex the keys you can use \array_values() ...
How can I negate the return-value of a process?
...at negates the value a process returns. It should map 0 to some value != 0 and any value != 0 to 0, i.e. the following command should return "yes, nonexistingpath doesn't exist":
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Difference between Select and ConvertAll in C#
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Select is a LINQ extension method and works on all IEnumerable<T> objects whereas ConvertAll is implemented only by List<T>. The ConvertAll method exists since .NET 2.0 whereas LINQ was introduced with 3.5.
You should favor Select over ConvertAll...