How can I sort the keys of a Hash so that they can be outputed
according to the keys sorted order?
Thanks.
A Hash is explicitly a non-sorted data structure. If you just want
the keys in sorted order, use:
hash.keys.sort
Look at other methods in Hash (e.g. sort) for more info.
Gavin
···
On Friday, January 3, 2003, 1:52:24 PM, TOTO wrote:
How can I sort the keys of a Hash so that they can be outputed
according to the keys sorted order?
Hi.
How can I sort the keys of a Hash so that they can be outputed
according to the keys sorted order?A Hash is explicitly a non-sorted data structure. If you just want
the keys in sorted order, use:hash.keys.sort
Look at other methods in Hash (e.g. sort) for more info.
You can also use hash.sort directly, however, be careful. It returns
an array of [key, value]. So to sort and iterate over the hash hash_a
do
hash_a.each { |item|
key = item[0]
value = item[1]
# do stuff ...
}
Regards,
-mark.
···
At 12:04 PM 1/3/2003 +0900, Gavin wrote:
On Friday, January 3, 2003, 1:52:24 PM, TOTO wrote:
Better:
hash_a.each do |key, value|
# do stuff
end
Gavin
···
On Friday, January 3, 2003, 2:16:29 PM, Mark wrote:
You can also use hash.sort directly, however, be careful. It returns
an array of [key, value]. So to sort and iterate over the hash hash_a
do
hash_a.each { |item| key = item[0] value = item[1] # do stuff ... }
I like:
hash.keys.sort.each do |key|
# do stuff with ~key~ and ~hash[key]~
end
Daniel
···
On Friday, January 3, 2003, 2:16:29 PM, Mark wrote:
You can also use hash.sort directly, however, be careful. It returns
an array of [key, value]. So to sort and iterate over the hash hash_a
do
Better:
hash_a.each do |key, value|
# do stuff
end
Hi.
You can also use hash.sort directly, however, be careful. It returns
an array of [key, value]. So to sort and iterate over the hash hash_a
dohash_a.each { |item|
My mistake. That should have been
hash_a.sort { |item| # item is array [key, value]
Sorry about the confusion.
-mark.
···
At 12:50 PM 1/3/2003 +0900, Gavin wrote:
On Friday, January 3, 2003, 2:16:29 PM, Mark wrote:
key = item[0] value = item[1] # do stuff ... }Better:
hash_a.each do |key, value|
# do stuff
end
My mistake. That should have been
hash_a.sort { |item| # item is array [key, value]
I don't understand, sorry, but Hash#sort will use the block to sort the
hash and item is [[key0, value0], [key1, value1]]
no ?
and you can write it
hash_a.sort do |(k0, v0), (k1, v1)|
# compare k0, v0, k1, v1
end
Guy Decoux
Hi, Guy.
···
At 11:42 PM 1/3/2003 +0900, Guy wrote:
My mistake. That should have been
hash_a.sort { |item| # item is array [key, value]I don’t understand, sorry, but Hash#sort will use the block to sort the
hash and item is [[key0, value0], [key1, value1]]
(I have to stop sprouting when I am sick … 
)
What I -meant- to say was “hash_a.sort.each”. So,
$ cat hash_a.rb
#! /usr/local/bin/ruby
hash_a = Hash.new
hash_a[“bob”] = 1
hash_a[“al”] = 2
hash_a[“zac”] = 3
hash_a[“moe”] = 4
puts “— each”
hash_a.each { |key, val|
puts “k=#{key} v=#{val}”
}
puts “— sort”
hash_a.sort.each { |item|
puts “k=#{item[0]} v=#{item[1]}”
}
$ ruby hash_a.rb
— each
k=al v=2
k=moe v=4
k=zac v=3
k=bob v=1
— sort
k=al v=2
k=bob v=1
k=moe v=4
k=zac v=3
–
My apologies for the wasted bandwidth.
-mark.