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Regex expressions in Java, \\s vs. \\s+
... regular expression quantifiers, and they perform matches like this (taken from the documentation):
Greedy quantifiers
X? X, once or not at all
X* X, zero or more times
X+ X, one or more times
X{n} X, exactly n times
X{n,} X, at least n times
X{n,m} X, at least n but not more than m times
...
How to declare and add items to an array in Python?
...se append
my_list.append(12)
To extend the list to include the elements from another list use extend
my_list.extend([1,2,3,4])
my_list
--> [12,1,2,3,4]
To remove an element from a list use remove
my_list.remove(2)
Dictionaries represent a collection of key/value pairs also known as an as...
Most efficient method to groupby on an array of objects
...efficient, as find() is probably O(n). The solution in the answer is O(n), from the reduce (object assignment is O(1), as is push), whereas the comment is O(n)*O(n) or O(n^2) or at least O(nlgn)
– narthur157
Jul 11 '18 at 10:47
...
Size-limited queue that holds last N elements in Java
...
Is there any callback called when element is evicted from the queue due to addition to full queue?
– ed22
May 2 '16 at 10:55
...
How do I delete an Azure storage account containing a leased blob?
...that the container has an active disk artifact and the advice to remove it from the repository.
The procedure to remove the disk image from the blob repository is:
Go to the Windows Azure Management Portal.
Click on Virtual Machines.
Click on Disks.
Click on the disk.
Click on Delete Disk.
Afte...
How to get current time and date in C++?
...
In C++ 11 you can use std::chrono::system_clock::now()
Example (copied from en.cppreference.com):
#include <iostream>
#include <chrono>
#include <ctime>
int main()
{
auto start = std::chrono::system_clock::now();
// Some computation here
auto end = std::chrono...
UIDevice uniqueIdentifier deprecated - What to do now?
... @DarkDust: but since the active interface changes when you switch from wifi to cellular modem, the MAC address of the active interface should also change; unless you always pick a particular interface to get the MAC
– user102008
Aug 27 '11 at 1:01
...
Is recursion ever faster than looping?
...n some environments these functions are the first (or only) to get a boost from automatic parallelization — so they can be significantly faster than either iteration or recursion. Data Parallel Haskell is an example of such an environment.
List comprehensions are another alternative, but these ...
When should an IllegalArgumentException be thrown?
...icate that a method has been passed an illegal or inappropriate argument.
From looking at how it is used in the JDK libraries, I would say:
It seems like a defensive measure to complain about obviously bad input before the input can get into the works and cause something to fail halfway through wi...
Hibernate Error: org.hibernate.NonUniqueObjectException: a different object with the same identifier
...mary key combination (column 1 and column 2). Now, you have removed 5 rows from the table at some point of time. Now, if you try to add the same 10 rows again, while hibernate tries to persist the objects in database, 5 rows which were already removed will be added without errors. Now the remaining ...