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Detecting arrow key presses in JavaScript
...ggered by onkeydown, not onkeypress.
The keycodes are:
left = 37
up = 38
right = 39
down = 40
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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
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Since dplyr 0.8 group_by gained the .drop argument that does just what you asked for:
df = data.frame(a=rep(1:3,4), b=rep(1:2,6))
df$b = factor(df$b, levels=1:3)
df %>%
group_by(b, .drop=FALSE) %>%
summarise(count_a=length(a))
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Ignore files that have already been committed to a Git repository [duplicate]
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edited Jul 16 '18 at 23:48
community wiki
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Code coverage with Mocha
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418
You need an additional library for code coverage, and you are going to be blown away by how powe...
Paperclip::Errors::MissingRequiredValidatorError with Rails 4
... with the spoofing validation explained here https://stackoverflow.com/a/23846121
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Is a Python dictionary an example of a hash table?
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zvyn
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answered Sep 22 '08 at 13:23
nosklonosklo
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Difference Between ViewData and TempData?
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answered Oct 6 '08 at 9:16
Dragan PanjkovDragan Panjkov
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Why does scanf() need “%lf” for doubles, when printf() is okay with just “%f”?
...effler
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answered Oct 16 '08 at 23:06
MSNMSN
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