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How do I get around type erasure on Scala? Or, why can't I get the type parameter of my collections?
It's a sad fact of life on Scala that if you instantiate a List[Int], you can verify that your instance is a List, and you can verify that any individual element of it is an Int, but not that it is a List[Int], as can be easily verified:
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Why start an ArrayList with an initial capacity?
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If you know in advance what the size of the ArrayList is going to be, it is more efficient to specify the initial capacity. If you don't do this, the internal array will have to be repeatedly reallocated as the list grows.
The larger the final list, the more time you save by avoiding the reall...
How do I create a constant in Python?
...annot declare a variable or value as constant in Python. Just don't change it.
If you are in a class, the equivalent would be:
class Foo(object):
CONST_NAME = "Name"
if not, it is just
CONST_NAME = "Name"
But you might want to have a look at the code snippet Constants in Python by Alex Martell...
How do you delete a column by name in data.table?
...l remove column foo from the data.table df3:
# Method 1 (and preferred as it takes 0.00s even on a 20GB data.table)
df3[,foo:=NULL]
df3[, c("foo","bar"):=NULL] # remove two columns
myVar = "foo"
df3[, (myVar):=NULL] # lookup myVar contents
# Method 2a -- A safe idiom for excluding (possibly m...
What's the difference between @Component, @Repository & @Service annotations in Spring?
Can @Component , @Repository and @Service annotations be used interchangeably in Spring or do they provide any particular functionality besides acting as a notation device?
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Strange out of memory issue while loading an image to a Bitmap object
I have a list view with a couple of image buttons on each row. When you click the list row, it launches a new activity. I have had to build my own tabs because of an issue with the camera layout. The activity that gets launched for the result is a map. If I click on my button to launch the image pre...
Window.open and pass parameters by post method
With window.open method I open new site with parameters, which I have to pass by post method.I've found solution, but unfortunately it doesn't work. This is my code:
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How can I unstage my files again after making a local commit?
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git reset --soft HEAD~1 should do what you want. After this, you'll have the first changes in the index (visible with git diff --cached), and your newest changes not staged. git status will then look like this:
# On branch ma...
Open a file with su/sudo inside Emacs
... I want to open a file in an existing Emacs session using su or sudo , without dropping down to a shell and doing sudoedit or sudo emacs . One way to do this is
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Safe String to BigDecimal conversion
...ing: "1,000,000,000.999999999999999" and I want to get a BigDecimal out of it. What is the way to do it?
9 Answers
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