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How to avoid warning when introducing NAs by coercion
... na = x %in% na.strings
x[na] = 0
x = as.numeric(x)
x[na] = NA_real_
x
}
as.num(c("1", "2", "X"), na.strings="X")
#[1] 1 2 NA
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Groovy / grails how to determine a data type?
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To determine the class of an object simply call:
someObject.getClass()
You can abbreviate this to someObject.class in most cases. However, if you use this on a Map it will try to retrieve the value with key 'class'. Because of this, I always use getClass() even thou...
How to sort an array of integers correctly
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By default, the sort method sorts elements alphabetically. To sort numerically just add a new method which handles numeric sorts (sortNumber, shown below) -
var numArray = [140000, 104, 99];
numArray.sort(function(a, b) {
return a - b;
});
console.log(numArray);
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How to center align the cells of a UICollectionView?
...nt, you could adjust that one too, if you want to center the content vertically in the screen.
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What is the difference between DSA and RSA?
...being a bit more complex than,
but related to El Gamal.
Note that nearly all the calculations are mod q, and
hence are much faster.
But, In contrast to RSA, DSA can be used only for digital signatures
DSA Security
The presence of a subliminal channel exists in many schemes (any that need a ran...
How to fix java.lang.UnsupportedClassVersionError: Unsupported major.minor version
I am trying to use Notepad++ as my all-in-one tool edit, run, compile, etc.
51 Answers
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Android list view inside a scroll view
...id:layout_marginTop="8dp"
android:text="This textview automatically goes below the Recycler View."
android:textSize="16sp" />
</androidx.appcompat.widget.LinearLayoutCompat>
</androidx.core.widget.NestedScrollView>
Now you can get rid of all the ugly hacks...
How do I force a UITextView to scroll to the top every time I change the text?
...here's too much hoop jumping to get things to behave the way they automatically should in most cases.
– John Contarino
Jun 9 '15 at 21:52
4
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What version of javac built my jar?
...ersion the class has been compiled FOR, not what version compiled it. Java allows you to compile code so that they're compatible with earlier versions of Java. However, this only applies to byte code and format. It will happily compile code that references JDK 6 libraries into a JDK 5 format, for ex...
How to import a class from default package
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Wow I really don't know java at all. That was a great help. Guess I'll have to move my class into a package...
– anhoppe
Jan 20 '16 at 20:14
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