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Practical uses for AtomicInteger
I sort of understand that AtomicInteger and other Atomic variables allow concurrent accesses. In what cases is this class typically used though?
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mongodb: insert if not exists
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Sounds like you want to do an "upsert". MongoDB has built-in support for this. Pass an extra parameter to your update() call: {upsert:true}. For example:
key = {'key':'value'}
data = {'key2':'value2', 'key3':'value3'};
coll.update(key, data, upsert=True); #In python ...
How to create a generic array in Java?
...that mean?
Checked: strong typing. GenSet knows explicitly what type of objects it contains (i.e. its constructor was explicitly called with a Class<E> argument, and methods will throw an exception when they are passed arguments that are not of type E. See Collections.checkedCollection.
-&g...
Invert “if” statement to reduce nesting
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A return in the middle of the method is not necessarily bad. It might be better to return immediately if it makes the intent of the code clearer. For example:
double getPayAmount() {
double result;
if (_isDead) result = deadAmount();
else {
if (_isSeparated) result = se...
Understanding the basics of Git and GitHub [closed]
I don't fully understand the purpose of using Git or Github; I know it helps to keep track of your changes and it's helpful for people collaborating with other people, but I don't collaborate with anybody so I don't know if this would be helpful for me.
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Retrieving the last record in each group - MySQL
There is a table messages that contains data as shown below:
27 Answers
27
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Convert PHP closing tag into comment
One of the lines in my script contains a PHP closing tag inside a string. Under normal operation this does not cause a problem, but I need to comment out the line.
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How to create a directory if it doesn't exist using Node.js?
Is this the right way to create a directory if it doesn't exist.
It should have full permission for the script and readable by others.
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explicit casting from super class to subclass
...ssignment Dog dog = (Dog) animal; does not generate a compilation error, but at runtime it generates a ClassCastException . Why can't the compiler detect this error?
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Static member initialization in a class template
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Just define it in the header:
template <typename T>
struct S
{
static double something_relevant;
};
template <typename T>
double S<T>::something_relevant = 1.5;
Since it is part of a template, as with all templates the compiler will make sure it's only d...