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Is there any performance reason to declare method parameters final in Java?
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The final keyword does not appear in the class file for local variables and parameters, thus it cannot impact the runtime performance. It's only use is to clarify the coders intent that the variable not be changed (which many consider dubious reason for its usage), and dealing with anonymous inn...
Get the position of a div/span tag
... the page. Basically you have to loop up through all the element's parents and add their offsets together.
function getPos(el) {
// yay readability
for (var lx=0, ly=0;
el != null;
lx += el.offsetLeft, ly += el.offsetTop, el = el.offsetParent);
return {x: lx,y: ly};
}
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How do I check in SQLite whether a table exists?
... the complete query is:
SELECT name FROM sqlite_master WHERE type='table' AND name='{table_name}';
Where {table_name} is the name of the table to check.
Documentation section for reference: Database File Format. 2.6. Storage Of The SQL Database Schema
This will return a list of tables with the...
What is the use for IHttpHandler.IsReusable?
I'm writing a IHttpHandler and I'll need to implement a IsReusable property. When I look at the MSDN documentation it says:
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Cannot change column used in a foreign key constraint
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The type and definition of foreign key field and reference must be equal.
This means your foreign key disallows changing the type of your field.
One solution would be this:
LOCK TABLES
favorite_food WRITE,
person WRITE;
AL...
How many random elements before MD5 produces collisions?
... quintillion 374 quadrillion 607 trillion 431 billion 768 million 211 thousand 456.
However if you keep all the hashes then the probability is a bit higher thanks to birthday paradox. To have a 50% chance of any hash colliding with any other hash you need 264 hashes. This means that to get a collis...
How can I round a number in JavaScript? .toFixed() returns a string?
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It returns a string because 0.1, and powers thereof (which are used to display decimal fractions), are not representable (at least not with full accuracy) in binary floating-point systems.
For example, 0.1 is really 0.100000000000000005551115123125782702118...
versionCode vs versionName in Android Manifest
I had my app in the android market with version code = 2 and version name = 1.1
10 Answers
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Removing pip's cache?
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Clear the cache directory where appropriate for your system
Linux and Unix
~/.cache/pip # and it respects the XDG_CACHE_HOME directory.
OS X
~/Library/Caches/pip
Windows
%LocalAppData%\pip\Cache
share
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AWS S3: how do I see how much disk space is using
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AWS Cloudwatch now has a metric for bucket size and number of objects that is updated daily. About time! aws.amazon.com/blogs/aws/…
– cudds
Jul 28 '15 at 23:13
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