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What is the difference between exit() and abort()?
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abort() exits your program without calling functions registered using atexit() first, and without calling objects' destructors first. exit() does both before exiting your program. It does not call destructors for automatic objects though. So
A a;
void test() ...
What is the difference between ${var}, “$var”, and “${var}” in the Bash shell?
...bar', so loop runs once and
done # prints nothing (actually "")
var="foo bar"
for i in "${var}bar"; do # Expands to 'for i in "foo barbar"; do...'
echo $i # so runs the loop once
done
# foo barbar
Note that "${var}bar" in the second example above could also ...
Why use @PostConstruct?
In a managed bean, @PostConstruct is called after the regular Java object constructor.
5 Answers
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C# int to byte[]
...sides, doing the assignment is cheap since it does not copy the memory nor allocate new memory, it just adds a new name to the already allocated array. So why not do it?
– paracycle
May 7 '19 at 15:54
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How to start two threads at “exactly” the same time
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// Now if we block on the gate from the main thread, it will open
// and all threads will start to do stuff!
gate.await();
System.out.println("all threads started");
This doesn't have to be a CyclicBarrier, you could also use a CountDownLatch or even a lock.
This still can't make sure that ...
Difference between malloc and calloc?
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calloc() gives you a zero-initialized buffer, while malloc() leaves the memory uninitialized.
For large allocations, most calloc implementations under mainstream OSes will get known-zeroed pages from the OS (e.g. via POSIX mm...
Configuring Log4j Loggers Programmatically
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You can add/remove Appender programmatically to Log4j:
ConsoleAppender console = new ConsoleAppender(); //create appender
//configure the appender
String PATTERN = "%d [%p|%c|%C{1}] %m%n";
console.setLayout(new PatternLayout(PATTERN));
console.setThresh...
How do I revert a Git repository to a previous commit?
...o temporarily go back to it, fool around, then come back to where you are, all you have to do is check out the desired commit:
# This will detach your HEAD, that is, leave you with no branch checked out:
git checkout 0d1d7fc32
Or if you want to make commits while you're there, go ahead and make a n...
What is the difference between pluck and collect in Rails?
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When you do:
User.first.gifts.collect(&:id)
You have objects with all fields loaded and you simply get the id thanks to the method based on Enumerable.
So:
if you only need the id with Rails 4, use ids: User.first.gifts.ids
if you only need some fields with Rails 4, use pluck: User.first...
“git pull” or “git merge” between master and development branches
...nges. I need to merge changes from master into develop , but will eventually merge everything from develop into master . I have two different workflows in mind:
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