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Java switch statement: Constant expression required, but it IS constant
...e compiler needs the expression to be known at compile time to compile a switch, but why isn't Foo.BA_ constant?
While they are constant from the perspective of any code that executes after the fields have been initialized, they are not a compile time constant in the sense required by the JLS; see...
What is x after “x = x++”?
...x does get incremented. But you are assigning the old value of x back into itself.
x = x++;
x++ increments x and returns its old value.
x = assigns the old value back to itself.
So in the end, x gets assigned back to its initial value.
...
How to change language settings in R
...g the Sys.setenv() function. My R session defaults to English, so I'll set it to French and then back again:
> Sys.setenv(LANG = "fr")
> 2 + x
Erreur : objet 'x' introuvable
> Sys.setenv(LANG = "en")
> 2 + x
Error: object 'x' not found
A list of the abbreviations can be found here.
S...
Can I see changes before I save my file in Vim?
I use Vim.
I open a file. I edit it and I want to see what I've edited before I save it.
14 Answers
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Set transparent background using ImageMagick and commandline prompt
Suppose you have any image (PNG or JPG).
This image has a white background and I need to make this background transparent.
...
how to convert from int to char*?
...follow
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edited Jan 7 '19 at 16:50
Cinder Biscuits
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SqlDataAdapter vs SqlDataReader
...:
Holds the connection open until you are finished (don't forget to close it!).
Can typically only be iterated over once
Is not as useful for updating back to the database
On the other hand, it:
Only has one record in memory at a time rather than an entire result set (this can be HUGE)
Is about a...
Should I store entire objects, or pointers to objects in containers?
...ou're considering using a std::vector and if updates are few and you often iterate over your collection and it's a non polymorphic type storing object "copies" will be more efficent since you'll get better locality of reference.
Otoh, if updates are common storing pointers will save the copy/reloc...
Remote debugging Tomcat with Eclipse
...
Actually, yours did fix it. Eclipse doesn't actually say anything when it successfully connects, and reconnecting a second time forces the error. So it was working, but I just didn't notice.
– victor
Oct 1 '1...
How to format a number as percentage in R?
...
Even later:
As pointed out by @DzimitryM, percent() has been "retired" in favor of label_percent(), which is a synonym for the old percent_format() function.
label_percent() returns a function, so to use it, you need an extra pair of parentheses.
library(sca...