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What is the purpose of the var keyword and when should I use it (or omit it)?
What exactly is the function of the var keyword in JavaScript, and what is the difference between
19 Answers
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What is the relationship between Looper, Handler and MessageQueue in Android?
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A Looper is a message handling loop: it reads and processes items from a MessageQueue. The Looper class is usually used in conjunction with a HandlerThread (a subclass of Thread).
A Handler is a utility class that facilitates interac...
How is Python's List Implemented?
Is it a linked list, an array? I searched around and only found people guessing. My C knowledge isn't good enough to look at the source code.
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What is an “unwrapped value” in Swift?
I'm learning Swift for iOS 8 / OSX 10.10 by following this tutorial , and the term " unwrapped value " is used several times, as in this paragraph (under Objects and Class ):
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How do you effectively model inheritance in a database?
...ch class which derives from it has its own table, with a primary key which is also a foreign key to the base class table; the derived table's class contains only the different elements.
So for example:
class Person {
public int ID;
public string FirstName;
public string LastName;
}
cl...
Lock, mutex, semaphore… what's the difference?
...A lock allows only one thread to enter the part that's locked and the lock is not shared with any other processes.
A mutex is the same as a lock but it can be system wide (shared by multiple processes).
A semaphore does the same as a mutex but allows x number of threads to enter, this can be used ...
What is the difference between up-casting and down-casting with respect to class variable
What is the difference between up-casting and down-casting with respect to class variable?
10 Answers
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Why is it bad practice to call System.gc()?
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The reason everyone always says to avoid System.gc() is that it is a pretty good indicator of fundamentally broken code. Any code that depends on it for correctness is certainly broken; any that rely on it for performance are most likely broken.
You don't know what sort of ga...
What are the benefits of Java's types erasure?
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Type Erasure Is Good
Let's stick to the facts
A lot of the answers thus far are overly concerned with the Twitter user. It's helpful to keep focused on the messages and not the messenger. There is a fairly consistent message with even j...
Is it safe to get values from a java.util.HashMap from multiple threads (no modification)?
There is a case where a map will be constructed, and once it is initialized, it will never be modified again. It will however, be accessed (via get(key) only) from multiple threads. Is it safe to use a java.util.HashMap in this way?
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