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What is the difference between square brackets and parentheses in a regex?
... that regex is trying to match << or >> or [[ or ]]. But from what you've said, it should be matching < or > or [ or ]. If you use | between [], do the brackets behave differently?
– Daniel Kaplan
Nov 14 '17 at 20:39
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What is the advantage of using forwarding references in range-based for loops?
....e. I wouldn't do this gratuitously because it does cause people to wonder what you're up to. And if I did do it, it wouldn't hurt to include a comment as to why:
#include <vector>
int main()
{
std::vector<bool> v(10);
// using auto&& so that I can handle the rvalue re...
What are the differences between “=” and “
What are the differences between the assignment operators = and <- in R?
7 Answers
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Constants in Objective-C
...and [NSString stringWithFormat:MyFirstConstant]. Make no assumptions about what instance of a string you have, even with literals. (In any case, #define is a "preprocessor directive", and is substituted before compilation, so either way the compiler sees a string literal in the end.)
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Grabbing the href attribute of an A element
...ink surrounded by either " or '
$str = '<a title="this" href="that">what?</a>';
preg_match('/^<a.*?href=(["\'])(.*?)\1.*$/', $str, $m);
var_dump($m);
Output:
array(3) {
[0]=>
string(37) "<a title="this" href="that">what?</a>"
[1]=>
string(1) """
[2]=>...
What is the garbage collector in Java?
I am new to Java and confused about the garbage collector in Java. What does it actually do and when does it comes into action. Please describe some of the properties of the garbage collector in Java.
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How to decide between MonoTouch and Objective-C? [closed]
...uirkiness of the Mono stack. However, since MonoTouch costs $400, I'm somewhat torn on if this is the way to go for iPhone development.
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What is causing this error - “Fatal error: Unable to find local grunt”
...grunt:init, which gives you options such as jQuery, node,commonjs. Select what you want, then proceed. This really works. For more information you can visit this.
Do this:
1. npm install -g grunt
2. grunt:init ( you will get following options ):
jquery: A jQuery plugin
node: A No...
Sleep in JavaScript - delay between actions
...ile sleeping (like doing progress updates, keeping some internal state, or whatever).
– Anders Sandvig
Feb 10 '10 at 8:28
5
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php is null or empty?
...
What you're looking for is:
if($variable === NULL) {...}
Note the ===.
When use ==, as you did, PHP treats NULL, false, 0, the empty string, and empty arrays as equal.
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