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Union Vs Concat in Linq
...mpare references of items. Your items have different references, thus they all are considered different. When you cast to base type X, reference is not changed.
If you will override Equals and GetHashCode (used to select distinct items), then items will not be compared by reference:
class X
{
...
Check for array not empty: any?
..." value in the array evaluates to true.
Similar methods to this are none?, all? and one?, where they all just check to see how many times true could be evaluated. which has nothing to do with the count of values found in a array.
case 1
>> a = []
=> []
>> a.any?
=> false
>> a...
Is it possible to make abstract classes in Python?
...nitions of those methods:
>>> Abstract()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: Can't instantiate abstract class Abstract with abstract methods foo
>>> class StillAbstract(Abstract):
... pass
...
>>> StillAbstr...
JOIN two SELECT statement results
...COUNT(*) AS '# Late' FROM Table WHERE Age > Palt GROUP BY ks
Or UNION ALL if you want duplicates:
SELECT ks, COUNT(*) AS '# Tasks' FROM Table GROUP BY ks
UNION ALL
SELECT ks, COUNT(*) AS '# Late' FROM Table WHERE Age > Palt GROUP BY ks
...
What does `node --harmony` do?
...aps, andweak maps))
type: bool default: false
--harmony (enable all harmony features (except typeof))
type: bool default: false
So --harmony is a shortcut to enable all the harmony features (e.g. --harmony_scoping, --harmony_proxies, etc.) From this blog post, it seems harmony e...
Resync git repo with new .gitignore file
... in ".gitignore file not ignoring" is a bit extreme, but should work:
# rm all files
git rm -r --cached .
# add all files as per new .gitignore
git add .
# now, commit for new .gitignore to apply
git commit -m ".gitignore is now working"
(make sure to commit first your changes you want to keep, to ...
In git, is there a way to show untracked stashed files without applying the stash?
...an stash untracked files. However, said untracked files don't show up at all with git stash show stash@{0} . Is there any way to show untracked stashed files without applying the stash?
...
Visual Studio 2010 annoyingly opens documents in wrong MDI pane
...ng the window layout and see if that fixes it.
First, Window -> Close All Documents
Then, Window -> Reset Window Layout
Exit VS to be sure, then go back in.
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Storing sex (gender) in database
...
I'd call the column "gender".
Data Type Bytes Taken Number/Range of Values
------------------------------------------------
TinyINT 1 255 (zero to 255)
INT 4 - 2,147,483,...
Makefile经典教程（入门必备） - C/C++ - 清泛网 - 专注IT技能提升
...定义的值。如：
foo = $(bar)
bar = $(ugh)
ugh = Huh?
all:
echo $(foo)
我们执行“make all”将会打出变量$(foo)的值是“Huh?”（ $(foo)的值是$(bar)，$(bar)的值是$(ugh)，$(ugh)的值是“Huh?”）可见，变量是可以使用后面的变量来...