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What does |= (single pipe equal) and &=(single ampersand equal) mean
...gnment operators, translating (very loosely)
x |= y;
into
x = x | y;
and the same for &. There's a bit more detail in a few cases regarding an implicit cast, and the target variable is only evaluated once, but that's basically the gist of it.
In terms of the non-compound operators, & ...
How to call base.base.method()?
...Special Derived.");
var ptr = typeof(Base).GetMethod("Say").MethodHandle.GetFunctionPointer();
var baseSay = (Action)Activator.CreateInstance(typeof(Action), this, ptr);
baseSay();
}
}
...
How do I delete rows in a data frame?
...
The key idea is you form a set of the rows you want to remove, and keep the complement of that set.
In R, the complement of a set is given by the '-' operator.
So, assuming the data.frame is called myData:
myData[-c(2, 4, 6), ] # notice the -
Of course, don't forget to "reassign" ...
F# development and unit testing?
... first functional language. I have been working quasi-exclusively with C#, and enjoy a lot how F# leads me to re-think how I write code. One aspect I find a bit disorienting is the change in the process of writing code. I have been using TDD for years in C# now, and really appreciate to have unit te...
How to use arguments from previous command?
I know that Esc + . gives you the last argument of the last command.
11 Answers
11...
Simplest way to read json from a URL in java
This might be a dumb question but what is the simplest way to read and parse JSON from URL in Java ?
11 Answers
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Android: Go back to previous activity
I want to do something simple on android app.
How is it possible to go back to a previous activity.
23 Answers
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How do you rotate a two dimensional array?
...e. Printing the matrix is the same complexitiy
– Alejandro
Aug 4 '15 at 20:34
6
For a -90 degrees...
What are important languages to learn to understand different approaches and concepts? [closed]
When all you have is a pair of bolt cutters and a bottle of vodka, everything looks like the lock on the door of Wolf Blitzer's boathouse. (Replace that with a hammer and a nail if you don't read xkcd)
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NSUserDefaults - How to tell if a key exists
I'm working on a small iPhone app, and I am using NSUserDefaults as my data persistence. It only has to keep track of a few things, such as some names and some numbers so I figure I might as well keep it simple.
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