Given an array like
["&abc", “a&cb”, “b&ac”, “ccc”, “cb&a”]
what is the Ruby way to construct an array containing only elements with
duplicate characters following the &'s? In this case
["&abc", “b&ac”, “cb&a”]
2006/5/5, Kyle A. [email protected]:
Given an array like
[“&abc”, “a&cb”, “b&ac”, “ccc”, “cb&a”]
what is the Ruby way to construct an array containing only elements with
duplicate characters following the &'s? In this case[“&abc”, “b&ac”, “cb&a”]
You can use select or inject. However it’s not clear to me what you
mean by “duplicate characters following the &'s”. Can you elaborate?
robert
On May 5, 2006, at 7:27 AM, Kyle A. wrote:
Given an array like
["&abc", “a&cb”, “b&ac”, “ccc”, “cb&a”]
what is the Ruby way to construct an array containing only elements
with
duplicate characters following the &'s? In this case["&abc", “b&ac”, “cb&a”]
["&abc", “a&cb”, “b&ac”, “ccc”, “cb&a”].grep(/&…/)
=> ["&abc", “a&cb”, “b&ac”]
Hope that helps.
James Edward G. II
James G. wrote:
["&abc", “a&cb”, “b&ac”, “ccc”, “cb&a”].grep(/&…/)
=> ["&abc", “a&cb”, “b&ac”]Hope that helps.
That’s not quite it. That seems to match all strings containing an
ampersand followed by 2 other characters. What I need is all strings
that have duplicate characters following an & (&a in the above).
Something a little more concrete:
["&File", “&Edit”, “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”, “&Help”]
would return
["&Edit", “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”]
(&e and &r are found multiple times).
Kyle A. wrote:
that have duplicate characters following an & (&a in the above).
Something a little more concrete:["&File", “&Edit”, “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”, “&Help”]
would return
["&Edit", “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”]
(&e and &r are found multiple times).
keys = {}
["&File", “&Edit”, “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”,
“&Help”].each do |l|
l =~ /&(.)/
(keys[ $1.downcase ] ||= []) << l
end
keys.values.select{|l| l.length > 1}.flatten
There’s almost certainly a better way…
What he’s saying is that he wants both “&Edit” and “Vi&ew” to show up
because both have an ‘e’ after the ampersand.
I take it these are identifiers for Windows menus or the like, so the
character after the ampersand has to be unique within a particular
set.
Here’s a quick attempt:
x = ["&Edit", “P&roject”, “Noamp”, “Vi&ew”, “S&le”, “T&ree”]
y = Hash.new { |h,k| h[k] = Array.new }
x.each do |s|
if m = /&(.)/.match(s)
y[m[1].downcase] << s
end
end
y.values.select { |v| v.size > 1 }.flatten
=> ["&Edit", “Vi&ew”, “P&roject”, “T&ree”]
On May 5, 2006, at 2:06 PM, Kyle A. wrote:
["&File", “&Edit”, “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”,
“&Help”]would return
["&Edit", “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”]
(&e and &r are found multiple times).
No letters are duplicated in “&Edit”.
I clearly don’t understand your goal, but you solve it like this:
array_of_strings.select do |string|
put test against string here…
end
Sorry I am not more help.
James Edward G. II
2006/5/5, Kyle A. [email protected]:
James G. wrote:
[“&abc”, “a&cb”, “b&ac”, “ccc”, “cb&a”].grep(/&…/)
=> [“&abc”, “a&cb”, “b&ac”]Hope that helps.
That’s not quite it. That seems to match all strings containing an
ampersand followed by 2 other characters. What I need is all strings
that have duplicate characters following an & (&a in the above).
By your definition “a&cb” does not belong into the result set.
Something a little more concrete:
[“&File”, “&Edit”, “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”, “&Help”]
would return
[“&Edit”, “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”]
(&e and &r are found multiple times).
Just for the fun of it:
irb(main):037:0> a=[“&File”, “&Edit”, “Vi&ew”, “P&roject”, “T&ree”,
“Favo&rites”, “&Help”]
=> [“&File”, “&Edit”, “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”,
“&Help”]
irb(main):038:0> a.inject(Hash.new {|h,k| h[k]=[]}) do |h,str|
irb(main):039:1* /&(.)/ =~ str and h[$1.downcase[0]] << str
irb(main):040:1> h
irb(main):041:1> end.values.select {|v| v.size > 1}.flatten
=> [“&Edit”, “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”]
irb(main):042:0> a.inject(Hash.new {|h,k| h[k]=[]}) do |h,str|
irb(main):043:1* /&(.)/ =~ str and h[$1.downcase[0]] << str
irb(main):044:1> h
irb(main):045:1> end.inject([]){|res,(k,v)| res.concat v if v.size >
1;res }
=> [“&Edit”, “Vi&ew”, “P&roject”, “T&ree”, “Favo&rites”]
Did I mention that inject is great?
:-))
robert