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Difference between ProcessBuilder and Runtime.exec()
...le string. The single-string overloads of exec() will tokenise the string into an array of arguments, before passing the string array onto one of the exec() overloads that takes a string array. The ProcessBuilder constructors, on the other hand, only take a varargs array of strings or a List of st...
COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
...ame as its table name:
CREATE TABLE fruit -- ORM-friendly name
(
fruit_id int NOT NULL,
fruit varchar(50), /* same name as table name,
and let's say, someone forgot to put NOT NULL */
shape varchar(50) NOT NULL,
color varchar(50) NOT NULL
)
Counting with null
And also, it is not...
Task vs Thread differences [duplicate]
... @LeonidVasilyev: Not directly Task related (this was before Tasks were introduced), but I did starve the thread pool once doing some image analysis work. I was using (too many really) the thread pool for object detection, but was pushing the results using an SDK which also used the threadpool. T...
Benefits of EBS vs. instance-store (and vice-versa) [closed]
...tched from S3.
If the hardware your EBS-backed instance is scheduled for maintenance, stopping and starting the instance automatically migrates to new hardware. I was also able to move an EBS-backed instance on failed hardware by force-stopping the instance and launching it again (your mileage may v...
How does PHP 'foreach' actually work?
...ng over an object, the packed representation that is normally used will be converted to a real dictionary. At that point, iteration of plain objects becomes very similar to iteration of arrays (which is why I'm not discussing plain-object iteration much in here).
So far, so good. Iterating over a d...
Find the Smallest Integer Not in a List
An interesting interview question that a colleague of mine uses:
28 Answers
28
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Null vs. False vs. 0 in PHP
...xt". Used to explicitly show you are dealing with logical issues.
0 is an int. Nothing to do with the rest above, used for mathematics.
Now, what is tricky, it's that in dynamic languages like PHP, all of them have a value in a boolean context, which (in PHP) is False.
If you test it with ==, it'...
Python: fastest way to create a list of n lists
...epeat
d = [[] for i in repeat(None, n)]
It does not have to create a new int object in every iteration and is about 15 % faster on my machine.
Edit: Using NumPy, you can avoid the Python loop using
d = numpy.empty((n, 0)).tolist()
but this is actually 2.5 times slower than the list comprehensi...
When should I use std::thread::detach?
...) the the destructor of an enclosing class?
– Jose Quinteiro
Nov 23 '16 at 17:59
4
@JoseQuinteiro...
Is the order of iterating through std::map known (and guaranteed by the standard)?
...p 's elements are sorted according to the keys. So, let's say the keys are integers. If I iterate from std::map::begin() to std::map::end() using a for , does the standard guarantee that I'll iterate consequently through the elements with keys, sorted in ascending order?
...