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Does Ruby regular expression have a not match operator like “!~” in Perl?
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Yes: !~ works just fine – you probably thought it wouldn’t because it’s missing from the...
What's the meaning of * (asterisk) in XAML ColumnDefinition?
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When you define a column in a WPF grid you can set the width to one of three possible values:
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jquery if div id has children
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edited Nov 29 '11 at 18:37
Joseph Silber
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Passing a URL with brackets to curl
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edited Jul 2 '19 at 20:14
moveson
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answe...
What does .SD stand for in data.table in R
...his is your data.table:
DT = data.table(x=rep(c("a","b","c"),each=2), y=c(1,3), v=1:6)
setkey(DT, y)
DT
# x y v
# 1: a 1 1
# 2: b 1 3
# 3: c 1 5
# 4: a 3 2
# 5: b 3 4
# 6: c 3 6
Doing this may help you see what .SD is:
DT[ , .SD[ , paste(x, v, sep="", collapse="_")], by=y]
# y V1
# 1...
Patterns for handling batch operations in REST web services?
...xample, to delete several messages at once.
DELETE /mail?&id=0&id=1&id=2
It's a little more complicated to batch update partial resources, or resource attributes. That is, update each markedAsRead attribute. Basically, instead of treating the attribute as part of each resource, you tr...
Formatting Numbers by padding with leading zeros in SQL Server
We have an old SQL table that was used by SQL Server 2000 for close to 10 years.
13 Answers
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Difference between variable declaration syntaxes in Javascript (including global variables)?
...l terms they're not usually big ones.
There's a fourth way, and as of ES2015 (ES6) there's two more. I've added the fourth way at the end, but inserted the ES2015 ways after #1 (you'll see why), so we have:
var a = 0; // 1
let a = 0; // 1.1 (new with ES2015)
const a = 0; // 1.2 (new with...
Get a filtered list of files in a directory
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14 Answers
14
Active
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Set operations (union, intersection) on Swift array?
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186
Yes, Swift has the Set class.
let array1 = ["a", "b", "c"]
let array2 = ["a", "b", "d"]
let ...