管理唯一值的csv字符串

Question

我有一串由逗号分隔的值，其顺序不重要，但值的唯一性是。我想值添加到字符串，我结束了类似

jruby-1.6.7 :009 > ("1,2,3,1".split(",").to_set << "1" << "4").to_a.join "," 
    => "1,2,3,4" 

这是有效的，但看起来很可怕，去串 - >排列 - >设置 - >排列 - >字符串，这是毫无疑问无效。什么是简单的方法来做到这一点？

Answer 1

您可以使用| （联盟）运营商。 例如

[ "1", "2", "3" ,"1"] | [ "1", "4"] 

这应当返还，

["1","2","3","4"] 

| （联合运算符）不会在字符串上工作。所以在你的情况下，可以使用

"1,2,3,4".split(",") | "1,4".split(",") 

=> [ “1”， “2”， “3”， “4”]

Answer 2

[*"1,2,3,1".split(","), "1", "4"].uniq.join "," 

Answer 3

require 'csv' 
str = "1,2,3,1" 
ar = CSV.parse(str) 
ar << ["1","4"] 
p ar.flatten.uniq.to_csv