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Sort hash by key, return hash in Ruby
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In Ruby 2.1 it is simple:
h.sort.to_h
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Is quoting the value of url() really necessary?
...ntax and basic data types
The format of a URI value is 'url(' followed by optional white space followed by an optional single quote (') or double quote (") character followed by the URI itself, followed by an optional single quote (') or double quote (") character followed by optional white spac...
How do I sort an array of hashes by a value in the hash?
This Ruby code is not behaving as I would expect:
4 Answers
4
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How to do the equivalent of pass by reference for primitives in Java
...ment " + toy.toyNumber);
}
Choice 2: return the value instead of pass by reference
int play(int toyNumber){
System.out.println("Toy number in play " + toyNumber);
toyNumber++;
System.out.println("Toy number in play after increement " + toyNumber);
return toyNumber
}
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How to use GROUP_CONCAT in a CONCAT in MySQL
..., ':', group_concat(`Value` separator ',')) as `Name`
from mytbl
group by
id,
`Name`
) tbl
group by id;
You can see it implemented here : Sql Fiddle Demo. Exactly what you need.
Update
Splitting in two steps. First we get a table having all values(comma separated) against a unique[N...
Assign multiple columns using := in data.table, by group
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f <- function(x) {list("hi", "hello")}
x[ , c("col1", "col2") := f(), by = a][]
# a b col1 col2
# 1: 1 1 hi hello
# 2: 2 2 hi hello
# 3: 3 3 hi hello
# 4: 1 4 hi hello
# 5: 2 5 hi hello
# 6: 3 6 hi hello
x[ , c("mean", "sum") := list(mean(b), sum(b)), by = a][]
# a b col1 c...
How to select the rows with maximum values in each group with dplyr? [duplicate]
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Try this:
result <- df %>%
group_by(A, B) %>%
filter(value == max(value)) %>%
arrange(A,B,C)
Seems to work:
identical(
as.data.frame(result),
ddply(df, .(A, B), function(x) x[which.max(x$value),])
)
#[1] TRUE
As pointed ...
How can I SELECT rows with MAX(Column value), DISTINCT by another column in SQL?
...N
(SELECT home, MAX(datetime) AS MaxDateTime
FROM topten
GROUP BY home) groupedtt
ON tt.home = groupedtt.home
AND tt.datetime = groupedtt.MaxDateTime
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Window Features - 更多技术 - 清泛网 - 专注C/C++及内核技术
... window used as a main window typically includes all of these components.
By specifying the WS_OVERLAPPED or WS_OVERLAPPEDWINDOW style in the CreateWindowEx function, an application creates an overlapped window. If you use the WS_OVERLAPPED style, the window has a title bar and border. If you use t...
Difference between filter and filter_by in SQLAlchemy
Could anyone explain the difference between filter and filter_by functions in SQLAlchemy?
Which one should I be using?
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