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What is an idempotent operation?
...ng, an idempotent operation is one that has no additional effect if it is called more than once with the same input parameters. For example, removing an item from a set can be considered an idempotent operation on the set.
In mathematics, an idempotent operation is one where f(f(x)) = f(x). For exa...
How do I get the coordinates of a mouse click on a canvas element?
...t are not necessary anymore, as the clientX and clientY properties work in all current browsers. You might want to check out Patriques Answer for a simpler, more recent solution.
Original Answer:
As described in an article i found back then but exists no longer:
var x;
var y;
if (e.pageX || e.page...
Is it possible to install APK file if more than one emulators/devices are connected [duplicate]
I know how to install the apk file in to the emulator by command prompt and all that.
But i want to know is it possible to install same apk file in to multiple emulator by giving any specific name ?
Actually i have to test one apk file in to many device. and for that i have started many device. I kn...
How do I print to the debug output window in a Win32 app?
...you can use the L prefix:
OutputDebugStringW(L"My output string.");
Normally you will use the macro version together with the _T macro like this:
OutputDebugString(_T("My output string."));
If you project is configured to build for UNICODE it will expand into:
OutputDebugStringW(L"My output s...
Force CloudFront distribution/file update
...
Good news. Amazon finally added an Invalidation Feature. See the API Reference.
This is a sample request from the API Reference:
POST /2010-08-01/distribution/[distribution ID]/invalidation HTTP/1.0
Host: cloudfront.amazonaws.com
Authorization:...
How to create a jQuery plugin with methods?
... plugin that will provide additional functions/methods to the object that calls it. All the tutorials I read online (have been browsing for the past 2 hours) include, at the most, how to add options, but not additional functions.
...
Pip freeze vs. pip list
...you are using a virtualenv, you can specify a requirements.txt file to install all the dependencies.
A typical usage:
$ pip install -r requirements.txt
The packages need to be in a specific format for pip to understand, which is
feedparser==5.1.3
wsgiref==0.1.2
django==1.4.2
...
That is the ...
SQL Server: Query fast, but slow from procedure
... the quoted answer did not solve the problem for me. The query still ran really slow from a stored procedure.
I found another answer here "Parameter Sniffing", Thanks Omnibuzz. Boils down to using "local Variables" in your stored procedure queries, but read the original for more understanding, it...
Pointers vs. values in parameters and return values
... function values, and interface values are implemented with pointers internally, and a pointer to them is often redundant.
Elsewhere, use pointers for big structs or structs you'll have to change, and otherwise pass values, because getting things changed by surprise via a pointer is confusing.
O...
boolean in an if statement
... will type coerce two things to be the same type and unless you understand all those rules and can anticipate everything that the JS interpreter might do when given two different types (which most JS developers cannot), you probably want to avoid == entirely.
As an example of how confusing it can b...