How do I convert an array to a string with two different delimiters at two different places in ruby?
I want to convert an array to a string with 2 different delimiters in 2 different places. which means:
array = [1,2,3,4]
after converting: separator 1: (":") separator 2: ("and")
string = "1:2:3: and 4"
OR
string = "1:2 and 3:4"
How can I build a dynamic and short code that allows me to convert an array (of any length) to a string that allows me to insert multiple delimiters and in different positions.
My current solution is messy and disgusting: I used #join with one argument.
def oxford_comma(array)
if array.length == 1
result_at_1 = array.join
return result_at_1
elsif array.length == 2
result_at_2 = array.join(" and ")
return result_at_2
elsif array.length == 3
last = array.pop
result = array.join(", ")
last = ", and " + last
result = result + last
elsif array.length > 3
last = array.pop
result = array.join(", ")
last = ", and " + last
result = result + last
return result
end
end
Can someone please help me to establish a better, shorter and more abstract way of doing this?
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You can use Enumerable # slice_after .
array.slice_after(1).map { |e| e.join ":" }.join(" and ") #=> "1 and 2:3:4"
array.slice_after(2).map { |e| e.join ":" }.join(" and ") #=> "1:2 and 3:4"
array.slice_after(3).map { |e| e.join ":" }.join(" and ") #=> "1:2:3 and 4"
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If you are using rails / activesupport it is built in :
[1,2,3,4].to_sentence # => "1, 2, 3, and 4"
[1,2].to_sentence # => "1 and 2"
[1,2,3,4].to_sentence(last_word_connector: ' and also ') # => "1, 2, 3 and also 4"
If you don't, then go to the activesupport implementation like :)
Note. This prevents you from placing your "and" in the middle of the sequence. Perfect for Oxford commas.
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code
def convert(arr, special_separators, default_separator, anchors={ :start=>'', :end=>'' })
seps = (0..arr.size-2).map { |i| special_separators[i] || default_separator }
[anchors.fetch(:start, ""), *[arr.first, *seps.zip(arr.drop(1)).map(&:join)],
anchors.fetch(:end, "")].join
end
<strong> Examples
arr = [1,2,3,4,5,6,7,8]
default_separator = ':'
# 1
special_separators = { 1=>" and ", 3=>" or " }
convert(arr, special_separators, default_separator)
#=> "1:2 and 3:4 or 5:6:7:8"
Where
seps #=> [":", " and ", ":", " or ", ":", ":", ":"]
# 2
special_separators = { 1=>" and ", 3=>") or (", 5=>" and " }
convert(arr, special_separators, default_separator, { start: "(", end: ")" })
#=> "(1:2 and 3:4) or (5:6 and 7:8)"
Where
seps #=> [":", " and ", ":", ") or (", ":", " and ", ":"]
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