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When should null values of Boolean be used?
...n in a database, for example). The null value might mean "we don't know if it's true or false" in this context.
each time a method needs an Object as argument, and you need to pass a boolean value. For example, when using reflection or methods like MessageFormat.format().
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What generates the “text file busy” message in Unix?
...r is accessing your file. Use lsof to check what other processes are using it. You can use kill command to kill it if needed.
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#ifdef replacement in the Swift language
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Yes you can do it.
In Swift you can still use the "#if/#else/#endif" preprocessor macros (although more constrained), as per Apple docs. Here's an example:
#if DEBUG
let a = 2
#else
let a = 3
#endif
Now, you must set the "DEBUG"...
Hidden features of Ruby
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edited Dec 8 '10 at 21:15
community wiki
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How do I choose between Tesseract and OpenCV? [closed]
I recently came across Tesseract and OpenCV . It looks like Tesseract is a full-fledged OCR engine and OpenCV can be used as a framework to create an OCR application/service.
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What does “static” mean in C?
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A static variable inside a function keeps its value between invocations.
A static global variable or a function is "seen" only in the file it's declared in
(1) is the more foreign topic if you're a newbie, so here's an example:
#include <stdio.h>
void foo()...
OwinStartup not firing
I had the OwinStartup configuration code working perfectly and then it stopped working. Unfortunately I'm not sure exactly what I did to get it to stop working and am having a really hard time figuring it out.
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View's getWidth() and getHeight() returns 0
...at I can rotate that button around. I am just trying to learn how to work with the android language. However, it returns 0.
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Get last n lines of a file, similar to tail
I'm writing a log file viewer for a web application and for that I want to paginate through the lines of the log file. The items in the file are line based with the newest item on the bottom.
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detect key press in python?
... key is pressed (such as p for pause and s for stop), and I would not like it to be something like raw_input that waits for the user's input before continuing execution. Anyone know how to do this in a while loop?
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