从字符串中提取子字符串并输出一些行

@斯皮克曼使用了 和 使 .*

string = "hello glass car [clock][flower] candy [apple]"

作为

string.scan(/\[(.*?)\]/)
  #=> [["clock"], ["flower"], ["apple"]]

我们会写

string.scan(/\[(.*?)\]/).flatten.each { |word| puts "#{word} have" }
clock have
flower have
apple have

或

string.scan(/\[(.*?)\]/).each { |(word)| puts "#{word} have" }
clock have
flower have
apple have

请注意,如果 non-greedy 如果从正则表达式中删除了限定符,我们将获得以下结果:

arr = string.scan(/\[(.*)\]/)
  #=> [["clock][flower] candy [apple"]]

也就是说,一个包含单个元素的数组,也就是一个包含单个元素的数组,字符串

"clock][flower] candy [apple"

String#scan ,特别是对(捕获)组的引用。

如问题所示,如果只想打印结果而不需要数组 ["clock", "flower", "apple"] ,您可以只编写以下内容:

string.gsub(/(?<=\[).*?(?=\])/) { |word| puts "#{word} have" }
clock have
flower have
apple have
  #=> "hello glass car [][] candy []"

或

string.gsub(/\[(.*?)\]/) { puts "#{$1} have" }
clock have
flower have
apple have
  #=> "hello glass car  candy "

丢弃返回值。

我会用 String#scan

string = "hello glass car [clock][flower] candy [apple]"
string.scan(/(?<=\[).*?(?=\])/).each { |word| puts "#{word} have" }