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How do you delete a column by name in data.table?
To get rid of a column named "foo" in a data.frame , I can do:
8 Answers
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Mercurial for Beginners: The Definitive Practical Guide
Inspired by Git for beginners: The definitive practical guide.
22 Answers
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How to declare a variable in MySQL?
How to declare a variable in mysql, so that my second query can use it?
7 Answers
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Is there a Mutex in Java?
Is there a Mutex object in java or a way to create one?
I am asking because a Semaphore object initialized with 1 permit does not help me.
Think of this case:
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How to use the toString method in Java?
Can anybody explain to me the concept of the toString() method, defined in the Object class? How is it used, and what is its purpose?
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Isn't “package private” member access synonymous with the default (no-modifier) access?
I am a little confused over the term "package private" that some of the documentation uses, along with the usage of "default access." Aren't package-private and default access both synonymous with protected?
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Should we pass a shared_ptr by reference or by value?
When a function takes a shared_ptr (from boost or C++11 STL), are you passing it:
10 Answers
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What REST PUT/POST/DELETE calls should return by a convention?
I've found a good post describing POST/PUT differences: POST vs PUT
But it still doesn't answer my question.
5 Answers
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How to use enums in C++
Suppose we have an enum like the following:
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What's the fastest way to delete a large folder in Windows?
I want to delete a folder that contains thousands of files and folders. If I use Windows Explorer to delete the folder it can take 10-15 minutes (not always, but often). Is there a faster way in Windows to delete folders?
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