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How does @synchronized lock/unlock in Objective-C?
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324
The Objective-C language level synchronization uses the mutex, just like NSLock does. Semantical...
How to count occurrences of a column value efficiently in SQL?
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Mike DinescuMike Dinescu
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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
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4 Answers
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Active
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Convert a char to upper case using regular expressions (EditPad Pro)
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answered Jul 21 '09 at 14:01
akfakf
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Grouping functions (tapply, by, aggregate) and the *apply family
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1344
+100
R has m...
Is 0 a decimal literal or an octal literal?
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Yes, 0 is an Octal literal in C++.
As per the C++ Standard:
2.14.2 Integer literals [lex.icon]
integer-literal:
decimal-literal integer-suffixopt
octal-literal integer-suffixopt
hexadecimal-literal integer-suffixopt
decimal-literal:
nonzero-digit
decima...
How to pass arguments and redirect stdin from a file to program run in gdb?
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moinudinmoinudin
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How to set the style -webkit-transform dynamically using JavaScript?
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edited Jun 15 '19 at 4:23
Cœur
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answe...
Disable Maven warning message - “Selected war files include a WEB-INF/web.xml which will be ignored”
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edited Jan 15 '16 at 16:49
Виталий Олегович
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How to make the 'cut' command treat same sequental delimiters as one?
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Try:
tr -s ' ' <text.txt | cut -d ' ' -f4
From the tr man page:
-s, --squeeze-repeats replace each input sequence of a repeated character
that is listed in SET1 with a single occurrence
of that character
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