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Best way to test for a variable's existence in PHP; isset() is clearly broken
... This looks a bit ugly to me, but in the case where you're actually checking an array element, it makes much more sense: isset($foo[$bar]) becomes array_key_exists($bar, $foo)
– Arild
Aug 25 '14 at 14:12
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What are the differences between -std=c++11 and -std=gnu++11?
...oid extensions because I don't recommend doing anything that isn't specifically defined by the Standard... but even then, "violates" is a strange and loaded term, when a lot of these extensions are, to use Standardese, just implementation-defining or specifying things that the Standard is silent on ...
How JavaScript closures are garbage collected
...e expected behavior.
From Mozilla's Memory management page: "As of 2012, all modern browsers ship a mark-and-sweep garbage-collector." "Limitation: objects need to be made explicitly unreachable".
In your examples where it fails some is still reachable in the closure. I tried two ways to make it...
How to count the number of files in a directory using Python
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For all kind of files, subdirectories included:
import os
list = os.listdir(dir) # dir is your directory path
number_files = len(list)
print number_files
Only files (avoiding subdirectories):
import os
onlyfiles = next(os.w...
MongoDB数据导出导入工具：mongoexport,mongoimport - 大数据 & AI - 清泛...
...个students集合，集合中数据如下：
> db.students.find()
{ "_id" : ObjectId("5031143350f2481577ea81e5"), "classid" : 1, "age" : 20, "name" : "kobe" }
{ "_id" : ObjectId("5031144a50f2481577ea81e6"), "classid" : 1, "age" : 23, "name" : "nash" }
{ "_id" : ObjectId("5031145a50f2481577ea81...
How do I get class name in PHP?
.... I found this out by trying to access the ::class property(?) of a dynamically generated class and getting the following error: Dynamic class names are not allowed in compile-time ::class fetch. See this answer for more details. I also found this note from the docs helpful.
–...
How do I output coloured text to a Linux terminal?
...
You need to output ANSI colour codes. Note that not all terminals support this; if colour sequences are not supported, garbage will show up.
Example:
cout << "\033[1;31mbold red text\033[0m\n";
Here, \033 is the ESC character, ASCII 27. It is followed by [, then zero o...
How to do parallel programming in Python?
For C++, we can use OpenMP to do parallel programming; however, OpenMP will not work for Python. What should I do if I want to parallel some parts of my python program?
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How to convert a scala.List to a java.util.List?
...1,2,3))
From Scala 2.8 onwards:
import scala.collection.JavaConversions._
import scala.collection.mutable.ListBuffer
asList(ListBuffer(List(1,2,3): _*))
val x: java.util.List[Int] = ListBuffer(List(1,2,3): _*)
However, asList in that example is not necessary if the type expected is a Java List,...
Vim: Replacing a line with another one yanked before
... If you overwrite additional lines with ccCTRL+r0ESC instead of V"0p then all following lines can be replaced with just . (the repeater)
– Jordan Morris
Aug 26 '13 at 5:10
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