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JavaScript, elegant way to check nested object properties for null/undefined [duplicate]
...e of using the app this gets populated. Let's say somwhere, after an AJAX call or something i do this:
4 Answers
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HashSet versus Dictionary w.r.t searching time to find if an item exists
...s for Dictionary is so fast that there is no benefit from using HashSet at all, in the OP's case.
– EtherDragon
Jul 27 '12 at 23:03
...
Glorified classes in the Java language
... lot of different answers, so I thought it would be useful to collect them all (and add some):
Classes
AutoBoxing classes - the compiler only allows for specific classes
Class - has its own literals (int.class for instance). I would also add its generic typing without creating new instances.
Stri...
MySQL Orderby a number, Nulls last
... tablename WHERE visible=1 ORDER BY -position DESC, id DESC
It is essentially the inverse of position DESC placing the NULL values last but otherwise the same as position ASC.
A good reference is here http://troels.arvin.dk/db/rdbms#select-order_by
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Forward function declarations in a Bash or a Shell script?
...
This seems somewhat analogous to what if _ _ name _ _ == "_ _ main _ _": main() does in python
– Sergiy Kolodyazhnyy
Feb 13 '16 at 7:13
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Python Image Library fails with message “decoder JPEG not available” - PIL
...you are on 64bit or 32bit Ubuntu.
For Ubuntu x64:
sudo ln -s /usr/lib/x86_64-linux-gnu/libjpeg.so /usr/lib
sudo ln -s /usr/lib/x86_64-linux-gnu/libfreetype.so /usr/lib
sudo ln -s /usr/lib/x86_64-linux-gnu/libz.so /usr/lib
Or for Ubuntu 32bit:
sudo ln -s /usr/lib/i386-linux-gnu/libjpeg.so /usr/l...
How do I check if a string contains another string in Swift?
... and containsIgnoringCase for String
extension String {
func contains(_ find: String) -> Bool{
return self.range(of: find) != nil
}
func containsIgnoringCase(_ find: String) -> Bool{
return self.range(of: find, options: .caseInsensitive) != nil
}
}
Older Swift vers...
Profiling Vim startup time
... if you want it to just print it, try vim --startuptime /dev/stdout +qall
– Capi Etheriel
Jan 15 '13 at 17:37
1
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What is a lambda (function)?
...us and refers to anonymous functions in programming.
Why is this cool? It allows you to write quick throw away functions without naming them. It also provides a nice way to write closures. With that power you can do things like this.
Python
def adder(x):
return lambda y: x + y
add5 = adder(5)...
Why is Scala's immutable Set not covariant in its type?
...ameter of type A due to the contravariance of functions. Set could potentially be contravariant in A, but this too causes issues when you want to do things like this:
def elements: Iterable[A]
In short, the best solution is to keep things invariant, even for the immutable data structure. You'll...