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What is the rationale behind having companion objects in Scala?
...eton) for a class is needed? Why would I want to create a class, say Foo and also create a companion object for it?
7 Ans...
What CSS selector can be used to select the first div within another div
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Agree that it's the ONLY correct answer to the question and it should be accepted.
– Ilya Streltsyn
Jul 17 '13 at 16:51
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Random shuffling of an array
I need to randomly shuffle the following Array:
29 Answers
29
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What is an idempotent operation?
...g that x in the mathematical definition represents the state of an object, and f is an operation that may mutate that object. For example, consider the Python set and its discard method. The discard method removes an element from a set, and does nothing if the element does not exist. So:
my_set.dis...
What does it mean in shell when we put a command inside dollar sign and parentheses: $(command)
I just want to understand following line of code in shell. It is used to get the current working directory. I am aware that $(variable) name return the value inside the variable name, but what is $(command) supposed to return? Does it return the value after executing the command? In that case, w...
Should I index a bit field in SQL Server?
...worth doing. I admit I don't know enough about how indexes work to understand why that is.
19 Answers
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Remove refs/original/heads/master from git repo after filter-branch --tree-filter?
.... Believe me, it's a really good idea.
Once you've inspected the results, and you're very confident that you have what you want, you can remove the backed up ref:
git update-ref -d refs/original/refs/heads/master
or if you did this to many refs, and you want to wipe it all out:
git for-each-ref...
Mechanisms for tracking DB schema changes [closed]
What are the best methods for tracking and/or automating DB schema changes? Our team uses Subversion for version control and we've been able to automate some of our tasks this way (pushing builds up to a staging server, deploying tested code to a production server) but we're still doing database up...
How to convert all text to lowercase in Vim
...rocessor). If you want to convert text to lowercase, create a visual block and press u (or U to convert to uppercase). Tilde (~) in command mode reverses case of the character under the cursor.
If you want to see all text in Vim in small caps, you might want to look at the guifont option, or type :s...
How to pass objects to functions in C++?
...C++11:
Pass by value, except when
you do not need ownership of the object and a simple alias will do, in which case you pass by const reference,
you must mutate the object, in which case, use pass by a non-const lvalue reference,
you pass objects of derived classes as base classes, in which case yo...