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How do you cast a List of supertypes to a List of subtypes?
...s Java tutorial
Assume there are two types A and B such that B extends A.
Then the following code is correct:
B b = new B();
A a = b;
The previous code is valid because B is a subclass of A.
Now, what happens with List<A> and List<B>?
It turns out that List<B> is n...
How to change the Eclipse default workspace?
...up the workspace you want is automatically loaded:
Go under preferences then type "workspace" in the search box provided to filter the list. Alternatively you can go to General>Startup and Shutdown>Workspaces.
There you can set a flag to make Eclipse prompt you to select a workspace at star...
Android Hello-World compile error: Intellij cannot find aapt
...did it, however, I had to select EARLY RELEASES, that showed the .4 update then when it restarted I got the 3.x which i denied. (Mac OS X 10.8.x)
– Martin Marconcini
May 28 '13 at 18:07
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How to define optional methods in Swift protocol?
Is it possible in Swift? If not then is there a workaround to do it?
19 Answers
19
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Throwing cats out of windows
...ution.
First, the probability of the cat dying is low (very low altitude), then it gets higher (low altitude), then again lower (higher altitude), and then again higher (very high altitude).
The graph for the probability of cat dying as a function of altitude above ground looks like this:
(finish a...
Double not (!!) operator in PHP
...ed twice. The right ! will result in a boolean, regardless of the operand. Then the left ! will negate that boolean.
This means that for any true value (numbers other than zero, non-empty strings and arrays, etc.) you will get the boolean value TRUE, and for any false value (0, 0.0, NULL, empty st...
Creating a new column based on if-elif-else condition
...> row['B']:
val = 1
else:
val = -1
return val
Then apply it to your dataframe passing in the axis=1 option:
In [1]: df['C'] = df.apply(f, axis=1)
In [2]: df
Out[2]:
A B C
a 2 2 0
b 3 1 1
c 1 3 -1
Of course, this is not vectorized so performance may not b...
Why do I need an IoC container as opposed to straightforward DI code? [closed]
... you make your properties virtual (calm down, it's not that big of a deal) then we can weave in that property behavior automatically. (This is called AOP, but don't worry about the name, focus on what it's going to do for you)
Depending on which IoC tool you're using, you could do something that l...
Ordering by the order of values in a SQL IN() clause
...
Two solutions that spring to mind:
order by case id when 123 then 1 when 456 then 2 else null end asc
order by instr(','||id||',',',123,456,') asc
(instr() is from Oracle; maybe you have locate() or charindex() or something like that)
...
Convert list to dictionary using linq and not worrying about duplicates
...y with a StringComparer that will ignore the case, if thats what you need, then your adding/checking code doesn't care if you're ignoring case or not.
– Binary Worrier
Jul 23 '10 at 15:06
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