在数组中搜索字符串及其在ruby中的子字符串

Question

我想在数组中搜索某个字符串和（！）其子字符串。例如，我的数组是：

array = ["hello", "hell", "goodbye", "he"]

所以当我搜索“hello”及其子串（但仅从头开始：“he”，“hell”，“hello”）时，它应该返回

=> ["hello", "hell", "he"]

到目前为止我尝试了什么：使用#grep和/或#include的正则表达式？像这样的方法：

array.grep("hello"[/\w+/])

或

array.select {|i| i.include?("hello"[/\w+/])}

但在这两种情况下它只返回

=> ["hello"] 

顺便说一下，如果我尝试array.select{|i| i.include?("he")}它的工作原理，但就像我说的那样，我想要反过来：搜索“你好”并从头开始给我所有结果，包括子串。

Answer 1

require "abbrev"

arr = ["hello", "hell", "goodbye", "he"]
p arr & ["hello"].abbrev.keys # => ["hello", "hell", "he"]

Answer 2

array = ["hello", "hell", "goodbye", "he", "he"]

# define search word:
search = "hello"

# find all substrings of this word:
substrings = (0..search.size - 1).each_with_object([]) { |i, subs| subs << search[0..i] }
#=> ["h", "he", "hel", "hell", "hello"]

# find intersection between array and substrings(will exclude duplicates):
p array & substrings
#=> ["hello", "hell", "he"]

# or select array elements that match any substring(will keep duplicates):
p array.select { |elem| substrings.include?(elem) }
#=> ["hello", "hell", "he", "he"]

Answer 3

将h中hello以外的所有字符变为可选字符。

> array = ["hello", "hell", "goodbye", "he"]
> array.select{|i| i[/^he?l?l?o?/]}
=> ["hello", "hell", "he"]

Answer 4

您仍然可以使用像这样的正则表达式

#define Array
arr = ["hello", "hell", "goodbye", "he"]
#define search term as an Array of it's characters
search = "hello".split(//)
#=> ['h','e','l','l','o']
#deem the first as manditory search.shift
#the rest are optional ['e?','l?','l?','o?'].join
search = search.shift << search.map{|a| "#{a}?"}.join
#=> "he?l?l?o?"
#start at the beginning of the string \A
arr.grep(/\A#{search}/)
#=> ["hello", "hell", "he"]

Answer 5

正如问题所示：

array.select { |w| "hello" =~ /^#{w}/ }
  #=> ["hello", "hell", "he"]

Answer 6

我使用String#[]：

array = ["hello", "hell", "goodbye", "he", "he"]
search = "hello"
array.select { |s| search[/\A#{s}/] }
# => ["hello", "hell", "he", "he"]

Answer 7

使用array#keep_if

array = ["hello", "hell", he"]
substrings = array.keep_if{|a| a.start_with?('h')}
=> ["hello", "hell", "he"]