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Function to clear the console in R and RStudio
...ws,
shell("clear") if on Linux or Mac.
(shell() passes a command (or any string) to the host terminal.)
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When would you use a WeakHashMap or a WeakReference?
...xProvider MUTEX_PROVIDER = new IdMutexProvider();
public void performTask(String resourceId) {
IdMutexProvider.Mutex mutext = MUTEX_PROVIDER.getMutex(resourceId);
synchronized (mutext) {
// look up the resource and do something with it
}
}
IdMutextProvider provides id-based ob...
Data structure: insert, remove, contains, get random element, all at O(1)
...il.Scanner;
public class JavaApplication1 {
public static void main(String args[]){
Scanner sc = new Scanner(System.in);
ArrayList<Integer> al =new ArrayList<Integer>();
HashMap<Integer,Integer> mp = new HashMap<Integer,Integer>();
whil...
vector::at vs. vector::operator[]
...y require it. (Microsoft pre-2010 was a bit of a problem here, since std::string didn't always work if the checking options didn't correspond with those of the runtime: -MD, and you'd better turn off checking, -MDd, and you'd better have it on.)
– James Kanze
...
What does the construct x = x || y mean?
... after the || (as far as i remember):
undefined
false
0
'' (Null or Null string)
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How to access class constants in Twig?
...od about this is that it makes it easy to use a Twig variable instead of a string literal as the constant name.
– CJ Dennis
Jun 6 '18 at 1:45
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Do NSUserDefaults persist through an Update to an app in the Appstore?
...a, NSUserDefaults is the best way to save data such as preferences, dates, strings etc. If you are looking to save images and files, the file system is a better bet.
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The import org.junit cannot be resolved
...ask how to run the Java class if it doesn't have a public static void main(String[] args)
– Luiggi Mendoza
Feb 27 '13 at 6:30
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Should I learn C before learning C++? [closed]
... that every book on C++ will not cover pointers and memory management, and string literals, etc.? I'm going to stop discussing now but feel free to leave your closing comments.
– Brian R. Bondy
Jun 23 '10 at 13:27
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How to remove element from an array in JavaScript?
...Benefits of this function is that you can use it on complex array not just string and number.
Some examples :
Remove first element :
// Not very useful but it works
function removeFirst(element, index) {
return index > 0;
}
var arr = [1,2,3,5,6].filter(removeFirst); // [2,3,4,5,6]
Rem...