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How to check if object (variable) is defined in R?
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heh. Happens to me all the time when I am testing out examples before posting, Gavin or Josh have already answered it.
– Maiasaura
Feb 20 '12 at 22:17
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How to declare a global variable in php?
...'];
}
From the Manual:
An associative array containing references to all variables which are currently defined in the global scope of the script. The variable names are the keys of the array.
If you have a set of functions that need some common variables, a class with properties may be a g...
Where is SQL Server Management Studio 2012?
... SQL Server 2008 R2 and Visual Studio 2008 and 2010 on my laptop. I've installed SQL Server 2012 and have finally got SQL Server Data Tools to show up, so that I can create SSRS reports in Visual Studio 2010.
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Python: One Try Multiple Except
...n) as e:
handle_either_of_3rd_4th_or_5th()
except Exception:
handle_all_other_exceptions()
See: http://docs.python.org/tutorial/errors.html
The "as" keyword is used to assign the error to a variable so that the error can be investigated more thoroughly later on in the code. Also note that...
How to open every file in a folder?
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Os
You can list all files in the current directory using os.listdir:
import os
for filename in os.listdir(os.getcwd()):
with open(os.path.join(os.cwd(), filename), 'r') as f: # open in readonly mode
# do your stuff
Glob
Or you c...
Is there a difference between YES/NO,TRUE/FALSE and true/false in objective-c?
Simple question really; is there a difference between these values (and is there a difference between BOOL and bool)? A co-worker mentioned that they evaluate to different things in Objective-C, but when I looked at the typedefs in their respective .h files, YES/TRUE/true were all defined as 1 an...
Should private helper methods be static if they can be static
...that they will not modify the state of the object. My IDE will also show calls to static methods in italics, so I will know the method is static without looking the signature.
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Unmangling the result of std::type_info::name
... calling function. This should be relatively easy, standard C++ has a type_info class. This contains the name of the typeid'd class/function/etc. but it's mangled. It's not very useful. I.e. typeid(std::vector<int>).name() returns St6vectorIiSaIiEE .
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What Automatic Resource Management alternatives exist for Scala?
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For now Scala 2.13 has finally supported: try with resources by using Using :), Example:
val lines: Try[Seq[String]] =
Using(new BufferedReader(new FileReader("file.txt"))) { reader =>
Iterator.unfold(())(_ => Option(reader.readLine()).ma...
Fast Linux File Count for a large number of files
...ke a while if there are a lot of them. Also there will be no output until all of the names are read and sorted. Use the ls -f option to turn off sorting.
ls -f | wc -l
Note that this will also enable -a, so ., .., and other files starting with . will be counted.
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