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ConcurrentHashMap vs Synchronized HashMap
...ference between using the wrapper class, SynchronizedMap , on a HashMap and ConcurrentHashMap ?
12 Answers
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How can I determine if a .NET assembly was built for x86 or x64?
...-bit Intel Itanium processor only.
MSIL: Neutral with respect to processor and bits-per-word.
X86: A 32-bit Intel processor, either native or in the Windows on Windows environment on a 64-bit platform (WOW64).
None: An unknown or unspecified combination of processor and bits-per-word.
I'm using Po...
How do I escape characters in c# comments?
...can not write a proper example since I don't know how to escape the < and > characters. Do I have to use &lt; and &gt; ? I don't like if that is the case since I want to make it easy to read the comment in the actual document so I don't have to generate some kind of code documen...
How to define a preprocessor symbol in Xcode
...o your Target or Project settings, click the Gear icon at the bottom left, and select "Add User-Defined Setting". The new setting name should be GCC_PREPROCESSOR_DEFINITIONS, and you can type your definitions in the right-hand field.
Per Steph's comments, the full syntax is:
constant_1=VALUE const...
Difference between $(window).load() and $(document).ready() functions
What is the difference between $(window).load(function() {}) and $(document).ready(function() {}) in jQuery?
11 Answers...
Is null an Object?
...case - any method invocation on a null results in a NullPointerException.
And this is what the Java Language Specification has to say on this topic:
There is also a special null type, the
type of the expression null, which has
no name. Because the null type has no
name, it is impossible t...
How to delete files/subfolders in a specific directory at the command prompt in Windows
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You can use this shell script to clean up the folder and files within C:\Temp source:
del /q "C:\Temp\*"
FOR /D %%p IN ("C:\Temp\*.*") DO rmdir "%%p" /s /q
Create a batch file (say, delete.bat) containing the above command. Go to the location where the delete.bat file is loc...
How to set variables in HIVE scripts
...where day >= ${hiveconf:CURRENT_DATE}
similarly, you could pass on command line:
% hive -hiveconf CURRENT_DATE='2012-09-16' -f test.hql
Note that there are env and system variables as well, so you can reference ${env:USER} for example.
To see all the available variables, from the command line, ...
How do I replace NA values with zeros in an R dataframe?
I have a data frame and some columns have NA values.
21 Answers
21
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How to link a folder with an existing Heroku app
I have an existing Rails app on GitHub and deployed on Heroku. I'm trying to set up a new development machine and have cloned the project from my GitHub repository. However, I'm confused as to how to link this folder up to Heroku. Originally, I used the heroku create command, but obviously I don't...