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Static nested class in Java, why?
I was looking at the Java code for LinkedList and noticed that it made use of a static nested class, Entry .
14 Answers
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Change default app.config at runtime
...te fields may work now, but it could use a warning that it isn't supported and may break in future versions of the .NET Framework.
– user743382
Mar 17 '15 at 9:36
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how perform grep operation on all files in a directory
Working with xenserver, and I want to perform a command on each file that is in a directory, grepping some stuff out of the output of the command and appending it in a file.
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Are duplicate keys allowed in the definition of binary search trees?
I'm trying to find the definition of a binary search tree and I keep finding different definitions everywhere.
12 Answers
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Should methods that throw RuntimeException indicate it in method signature?
... API. It is no longer obvious whether the exception has to be explicitly handled.
Declaring it in the javadoc is a better approach since it allows someone to handle it if they think it is necessary, but knowing they can ignore it if they want. This makes the separation between checked and uncheck...
Oracle SQL escape character (for a '&')
...ent of user priveleges (i.e. when users are not allowed to SET DEFINE OFF) and for when users want to specify both ampersands in text and defined variables in the same SQL command.
– Fuzzy Analysis
Oct 31 '13 at 22:26
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The best way to remove duplicate values from NSMutableArray in Objective-C?
...wrote the answer below in 2009; in 2011, Apple added NSOrderedSet to iOS 5 and Mac OS X 10.7. What had been an algorithm is now two lines of code:
NSOrderedSet *orderedSet = [NSOrderedSet orderedSetWithArray:yourArray];
NSArray *arrayWithoutDuplicates = [orderedSet array];
If you are worried ab...
Why do we check up to the square root of a prime number to determine if it is prime?
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If a number n is not a prime, it can be factored into two factors a and b:
n = a * b
Now a and b can't be both greater than the square root of n, since then the product a * b would be greater than sqrt(n) * sqrt(n) = n. So in any factorization of n, at least one of the factors must be smal...
Asking the user for input until they give a valid response
...put the input method in a while loop. Use continue when you get bad input, and break out of the loop when you're satisfied.
When Your Input Might Raise an Exception
Use try and except to detect when the user enters data that can't be parsed.
while True:
try:
# Note: Python 2.x users s...
How to call a Parent Class's method from Child Class in Python?
... able to invoke methods of the parent class from a derived class. In Perl and Java, there is a keyword for this ( super ). In Perl, I might do this:
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