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How do you trigger a block after a delay, like -performSelector:withObject:afterDelay:?
Is there a way to call a block with a primitive parameter after a delay, like using performSelector:withObject:afterDelay: but with an argument like int / double / float ?
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Difference between EXISTS and IN in SQL?
What is the difference between the EXISTS and IN clause in SQL?
21 Answers
21
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How to read data when some numbers contain commas as thousand separator?
I have a csv file where some of the numerical values are expressed as strings with commas as thousand separator, e.g. "1,513" instead of 1513 . What is the simplest way to read the data into R?
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Picking a random element from a set
How do I pick a random element from a set?
I'm particularly interested in picking a random element from a
HashSet or a LinkedHashSet, in Java.
Solutions for other languages are also welcome.
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What must I know to use GNU Screen properly? [closed]
I've just introduced a friend to GNU Screen and they're having a hard time getting used to it. That makes me think about the essential things he needs to know about the excellent Screen utility, the same things that you'd think worthwhile to teach someone, a beginner, from the ground up. What ar...
How do I use boolean variables in Perl?
I have tried:
8 Answers
8
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Practical uses of different data structures [closed]
There's a lot of talk about data structures, but I can't find a simple list of data structures and their practical use out there. I'm trying to study for an interview and I think this would help me out, along with many others. I'm looking for something like this:
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Converting Select results into Insert script - SQL Server [closed]
I have SQL Server 2008 , SQL Server Management Studio.
18 Answers
18
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What is a sensible way to layout a Go project [closed]
I have a go project that is starting to become more complex, and want to lay the filesystem out in such a way to reduce pain.
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Best way to define error codes/strings in Java?
I am writing a web service in Java, and I am trying to figure out the best way to define error codes and their associated error strings . I need to have a numerical error code and an error string grouped together. Both the error code and error string will be sent to the client accessing the web ser...