Select 特定 两个字符串之间的文本（多行）

Question

I want to Select specific text between two strings using regex.

eg:

 foo I have four toys bar //single line foo //multiline I have four toys bar foo I have three pets bar foo I have three pets bar

How to select text between "foo" and "bar" with specific word containing "four"

Output:

 I have four toys I have four toys

My code:

 foo[\s\S]*?(four)[\s\S]*?bar

My code is working fine but problem is that when when "four" word does not comes between "foo" and "bar" it is selecting all text till "four" word

foo I have three pets bar foo I have four toys bar foo I have three pets bar

I just want text between "foo" and "bar" when it is containg specific word "four"

Answer 1

We can use the following regex pattern, in dot all mode:

 \bfoo\s+(?:(?.\bbar\b)?)*?\s+four\s+(:?(.?\bfoo\b) )* \s+bar

 var input = `foo I have four toys bar foo I have four toys bar foo I have three pets bar foo I have three pets bar`; var matches = input.match(/\bfoo\s+(?:(?.\bbar\b)?)*?\s+four\s+(:?(.?\bfoo\b).)*.\s+bar/gs),map(x => x;replace(/^foo\s+|\s+bar$/g. "")); console log(matches)

An explanation to this complex regex pattern might be helpful here:

 \bfoo\s+ match 'foo' followed by one or more whitespace characters (?:(?.\bbar\b)?)*? match any content WITHOUT encountering 'bar' \s+four\s+ match 'four' surrounded by whitespace (:?(.?\bfoo\b) )* match any content WITHOUT encountering 'foo' \s+bar whitespace followed by ending 'bar'

Note that due to the way match() behaves, we also have a map step where we strip off leading foo and ending bar from every match.