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'AND' vs '&&' as operator
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If you use AND and OR, you'll eventually get tripped up by something like this:
$this_one = true;
$that = false;
$truthiness = $this_one and $that;
Want to guess what $truthiness equals?
If you said false... bzzzt, sorry, wrong!
$truthiness above has the ...
Quicksort vs heapsort
... The most direct competitor of
quicksort is heapsort. Heapsort is
typically somewhat slower than
quicksort, but the worst-case running
time is always Θ(nlogn). Quicksort is
usually faster, though there remains
the chance of worst case performance
except in the introsort variant, which...
Can I restore a single table from a full mysql mysqldump file?
I have a mysqldump backup of my mysql database consisting of all of our tables which is about 440 megs. I want to restore the contents of just one of the tables from the mysqldump. Is this possible? Theoretically, I could just cut out the section that rebuilds the table I want but I don't even know ...
Does JavaScript have a built in stringbuilder class?
... strings with the + or += operator are extremely slow on IE. This is especially true for IE6. On modern browsers += is usually just as fast as array joins.
When I have to do lots of string concatenations I usually fill an array and don't use a string builder class:
var html = [];
html.push(
"&l...
CSS: How to position two elements on top of each other, without specifying a height?
...exactly on top of each other. However, when I do that, the formatting gets all screwed up because the containing DIV acts like there is no height. I think this is the expected behavior with position:absolute but I need to find a way to position these two elements on top of each other and have the ...
jquery.validate.unobtrusive not working with dynamic injected elements
...ate it to include the code in the comments otherwise it can break. Specifically, change the two selector lines to double quote the id.
– Ryan O'Neill
Jul 14 '11 at 19:50
1
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What character encoding should I use for a HTTP header?
...com/ for more info) for a Server HTTP-header and am wondering if it is "allowed" per spec.
2 Answers
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What is InnoDB and MyISAM in MySQL?
...MyISAM
InnoDB is a storage engine for MySQL,
included as standard in all current
binaries distributed by MySQL AB. Its
main enhancement over other storage
engines available for use with MySQL
is ACID-compliant transaction support
MyISAM is the default storage engine
for the MySQ...
SQL Joins Vs SQL Subqueries (Performance)?
...explicit JOIN. In my experience IN is a very slow operator, since SQL normally evaluates it as a series of WHERE clauses separated by "OR" (WHERE x=Y OR x=Z OR...).
As with ALL THINGS SQL though, your mileage may vary. The speed will depend a lot on indexes (do you have indexes on both ID column...
Why does Apple recommend to use dispatch_once for implementing the singleton pattern under ARC?
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dispatch_once() is absolutely synchronous. Not all GCD methods do things asynchronously (case in point, dispatch_sync() is synchronous). The use of dispatch_once() replaces the following idiom:
+ (MyClass *)sharedInstance {
static MyClass *sharedInstance;
@synchr...