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Difference between a class and a module
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@Caffeine not really because Ruby modules actually include implementations, whereas interfaces in Java are abstract
– Jorge Israel Peña
Jan 12 '13 at 6:34
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How does one reorder columns in a data frame?
... has four columns like so df[,c(1,2,3,4)].
Note the first comma means keep all the rows, and the 1,2,3,4 refers to the columns.
To change the order as in the above question do df2[,c(1,3,2,4)]
If you want to output this file as a csv, do write.csv(df2, file="somedf.csv")
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SQL query to get all values a enum can have
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The unnest call will return records of type myenum with a column name of "myenum". You might also want to cast the enum to text and specify a column name by adding something like. ::text AS my_column
– Justin Oh...
How to avoid reverse engineering of an APK file?
...cker is able to change it in any way she or he finds it feasible. You basically can't protect your application from being modified. And any protection you put in there can be disabled/removed.
2. How can I protect all the app's resources, assets and source code so that hackers can't hack the A...
What does a Ajax call response like 'for (;;); { json data }' mean? [duplicate]
I found this kind of syntax being used on Facebook for Ajax calls. I'm confused on the for (;;); part in the beginning of response. What is it used for?
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Difference between Activity Context and Application Context
...nformation about the current activity that is necessary to complete those calls. If you show the exact error message, might be able to point to what exactly it needs.
But in general, use the activity context unless you have a good reason not to.
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How to make links in a TextView clickable?
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// respond to user input. To make them active, you need to
// call setMovementMethod() on the TextView object.
TextView t2 = (TextView) findViewById(R.id.text2);
t2.setMovementMethod(LinkMovementMethod.getInstance());
I removed most of the attributes on my TextView to match wh...
How to remove a TFS Workspace Mapping?
...stating "Show Remote Workspaces" - just tick that and you'll get a list of all your enlistments:
From the command line
Call "tf workspace" from a developer command prompt. It will bring up the "Manage Workspaces" directly!
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How does the compilation/linking process work?
... #include directives with the content of the respective files (which is usually just declarations), doing replacement of macros (#define), and selecting different portions of text depending of #if, #ifdef and #ifndef directives.
The preprocessor works on a stream of preprocessing tokens. Macro subs...
Generate random numbers using C++11 random library
... functions and why not to use rand(). In it, he included a slide that basically solves your question. I've copied the code from that slide below.
You can see his full talk here: http://channel9.msdn.com/Events/GoingNative/2013/rand-Considered-Harmful
#include <random>
#include <iostream&g...