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Best way to iterate through a Perl array
...ay elements occurs. ($_ is aliased to the element in #1, but #2 and #3 actually copy the scalars from the array.)
#5 might be similar.
In terms memory usage: They're all the same except for #5.
for (@a) is special-cased to avoid flattening the array. The loop iterates over the indexes of the array...
New self vs. new static
...the first method, whereas static is bound to the called class (also see get_called_class()).
class A {
public static function get_self() {
return new self();
}
public static function get_static() {
return new static();
}
}
class B extends A {}
echo get_class(B::ge...
In Python how should I test if a variable is None, True or False
...
a = 'foo' if a: print 'its true' a is not actually TRUE, it's just not none
– wesm
Apr 3 '15 at 21:06
...
What does the 'b' character do in front of a string literal?
...
Actually, if you've imported unicode_literals from __future__, this will "reverse" the behavior for this particular string (in Python 2.x)
– Romuald Brunet
Mar 14 '13 at 16:27
...
List all the files that ever existed in a Git repository
Do you have a clean way to list all the files that ever existed in specified branch?
4 Answers
...
Creating the Singleton design pattern in PHP5
...
/**
* Singleton class
*
*/
final class UserFactory
{
/**
* Call this method to get singleton
*
* @return UserFactory
*/
public static function Instance()
{
static $inst = null;
if ($inst === null) {
$inst = new UserFactory();
...
How to split a long regular expression into multiple lines in JavaScript?
...
You could convert it to a string and create the expression by calling new RegExp():
var myRE = new RegExp (['^(([^<>()[\]\\.,;:\\s@\"]+(\\.[^<>(),[\]\\.,;:\\s@\"]+)*)',
'|(\\".+\\"))@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.',
...
Get operating system info
...x]{2})', 'Windows');
// Doesn't seem like these are necessary...not totally sure though..
//$ros[] = array('(winnt)([0-9]{1,2}\.[0-9]{1,2}){0,1}', 'Windows NT');
//$ros[] = array('(windows nt)(([0-9]{1,2}\.[0-9]{1,2}){0,1})', 'Windows NT'); // fix by bg
$ros[] = array('Windows ME', '...
What is dynamic programming? [closed]
...ith dynamic programming, you store your results in some sort of table generally. When you need the answer to a problem, you reference the table and see if you already know what it is. If not, you use the data in your table to give yourself a stepping stone towards the answer.
The Cormen Algorithms ...
Why doesn't list have safe “get” method like dictionary?
...accessing list elements (as the len method is very fast). The .get method allows you to query the value associated with a name, not directly access the 37th item in the dictionary (which would be more like what you're asking of your list).
Of course, you can easily implement this yourself:
def sa...