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How to check if a number is a power of 2
...eturn (x != 0) && ((x & (x - 1)) == 0);
}
Explanation
First and foremost the bitwise binary & operator from MSDN definition:
Binary & operators are predefined for the integral types and bool. For
integral types, & computes the logical bitwise AND of its operands.
F...
I want to remove double quotes from a String
...s).
Here's how it works:
['"] is a character class, matches both single and double quotes. you can replace this with " to only match double quotes.
+: one or more quotes, chars, as defined by the preceding char-class (optional)
g: the global flag. This tells JS to apply the regex to the entire st...
Using jQuery to compare two arrays of Javascript objects
...that I'd like to compare to see if they are the same. The objects may not (and most likely will not) be in the same order in each array. Each array shouldn't have any more than 10 objects. I thought jQuery might have an elegant solution to this problem, but I wasn't able to find much online.
...
Batch script: how to check for admin rights
...erything except Windows 8. Running AT on Windows 8 results in:
The AT command has been deprecated. Please use schtasks.exe instead.
The request is not supported.
(see screenshot #1) and will return %errorLevel% 1.
Research
So, I went searching for other commands that require elevated permi...
“CASE” statement within “WHERE” clause in SQL Server 2008
...tatements like this:
WHERE (
(LEN('TestPerson') = 0
AND co.personentered = co.personentered
)
OR
(LEN('TestPerson') <> 0
AND co.personentered LIKE '%TestPerson')
)
Although, either way I'm not sure how great of a query plan...
What is the equivalent of MATLAB's repmat in NumPy
... repmat(a, m, n) is tile(a, (m, n)).
This works with multiple dimensions and gives a similar result to matlab. (Numpy gives a 3d output array as you would expect - matlab for some reason gives 2d output - but the content is the same).
Matlab:
>> repmat([1;1],[1,1,1])
ans =
1
1
...
Why is January month 0 in Java Calendar?
...a date/time API. Listing what's wrong with it would take a very long time (and I'm sure I don't know half of the problems). Admittedly working with dates and times is tricky, but aaargh anyway.
Do yourself a favour and use Joda Time instead, or possibly JSR-310.
EDIT: As for the reasons why - as n...
How can I sort arrays and data in PHP?
... sorts low-to-high or reverse ("r"), whether it sorts values or keys ("k") and how it compares values ("nat" vs. normal). See http://php.net/manual/en/array.sorting.php for an overview and links to further details.
Multi dimensional arrays, including arrays of objects
$array = array(
array('foo'...
Calculating frames per second in a game
...asiest way is to take the current answer (the time to draw the last frame) and combine it with the previous answer.
// eg.
float smoothing = 0.9; // larger=more smoothing
measurement = (measurement * smoothing) + (current * (1.0-smoothing))
By adjusting the 0.9 / 0.1 ratio you can change the 'tim...
How do you set, clear, and toggle a single bit?
How do you set, clear, and toggle a bit?
30 Answers
30
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