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What is an idempotent operation?
...g that x in the mathematical definition represents the state of an object, and f is an operation that may mutate that object. For example, consider the Python set and its discard method. The discard method removes an element from a set, and does nothing if the element does not exist. So:
my_set.dis...
A complete solution to LOCALLY validate an in-app receipts and bundle receipts on iOS 7
I have read a lot of docs and code that in theory will validate an in-app and/or bundle receipt.
3 Answers
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Timer function to provide time in nano seconds using C++
...ed about running the function repeatedly in a loop is correct.
For Linux (and BSD) you want to use clock_gettime().
#include <sys/time.h>
int main()
{
timespec ts;
// clock_gettime(CLOCK_MONOTONIC, &ts); // Works on FreeBSD
clock_gettime(CLOCK_REALTIME, &ts); // Works on Li...
Add margin between a RadioButton and its label in Android?
Is it possible to add a little bit of space between a RadioButton and the label while still using Android's built-in components? By default the text looks a little scrunched.
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Uses for Optional
...eem to swing between wanting to use it everywhere something may be null , and nowhere at all.
14 Answers
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Upgrading Node.js to latest version
So, I have Node.js installed and now when I tried to install Mongoosejs I got an error telling me that I don't have the needed version of Node.js (I have v0.4.11 and v0.4.12 is needed).
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How to change port number for apache in WAMP
I am new to WAMP server and installed it on my system but after installing it when I check it by going to localhost url like this http://localhost/ in the browser it is not working. I am getting a 404 error and blank page .
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Why does jQuery or a DOM method such as getElementById not find the element?
...ers parse HTML documents from top to bottom. Elements are added to the DOM and scripts are (generally) executed as they're encountered. This means that order matters. Typically, scripts can't find elements which appear later in the markup because those elements have yet to be added to the DOM.
Cons...
How to get the connection String from a database
...the "Server Explorer" window in Visual Studio (menu View, Server Explorer) and connect to the server from that window.
Then you can see the connection string in the properties of the connected server (choose the connection and press F4 or Alt+Enter or choose Properties on the right click menu).
Ad...
Difference between final and effectively final
I'm playing with lambdas in Java 8 and I came across warning local variables referenced from a lambda expression must be final or effectively final . I know that when I use variables inside anonymous class they must be final in outer class, but still - what is the difference between final and ef...