javascript - Regular expression to match the content of the innermost bracket

Now there is a string:

<code>str1 = '(subject_id = "A" OR (status_id = "Open" AND (status_id = "C" OR level_id = "D")))'
</code>

or

<code>str2 = '(subject_id = "A" OR subject_id = "Food" OR (subject_id = "C" OR (status_id = "Open" AND (status_id = "C" OR (level_id = "D" AND subject_id = "(Cat)")))))'
</code>

I need to match the innermost brackets in the string and the content inside them (not matching brackets within quotation marks) through regular expressions, that is:

<code>str1 => (status_id = "C" OR level_id = "D")

str2 => (level_id = "D" AND subject_id = "(Cat)")
</code>

So, how should we write this super complex regular expression?

If regular expression cannot be implemented, how can it be implemented with JS?

---

Added, for str1, I found such a regular expression that can satisfy the matching:

<code>\([^()]+\)
</code>

But for str2, there is still no solution. I look forward to everyone’s answers!

Reply content:

Now there is a string:

<code>str1 = '(subject_id = "A" OR (status_id = "Open" AND (status_id = "C" OR level_id = "D")))'
</code>

or

<code>str2 = '(subject_id = "A" OR subject_id = "Food" OR (subject_id = "C" OR (status_id = "Open" AND (status_id = "C" OR (level_id = "D" AND subject_id = "(Cat)")))))'
</code>

I need to match the innermost brackets in the string and the content inside them (not matching brackets within quotation marks) through regular expressions, that is:

<code>str1 => (status_id = "C" OR level_id = "D")

str2 => (level_id = "D" AND subject_id = "(Cat)")
</code>

So, how should we write this super complex regular expression?

If regular expression cannot be implemented, how can it be implemented with JS?

---

Added, for str1, I found such a regular expression that can satisfy the matching:

<code>\([^()]+\)
</code>

But for str2, there is still no solution. I look forward to everyone’s answers!

For str2, I found this

<code>\([^()]*\"[^"]*\"[^()]*\)</code>

After looking at the requirements, I didn’t consider using regular expressions at all. It seemed too complicated... Let’s just use the traditional method;
You can use the idea of ​​operation priority, that is, use the stackdata structure to obtain the contents of the inner brackets ;
Technical points:

1. Match the innermost bracket

2. Contents within quotation marks are not used as matching criteria

Start designing the algorithm based on this idea:
The algorithm calculates the startIndex and endIndex of the substring to be matched and then uses the substring() method to obtain the substring;

• When a "(" character is matched, is pushed onto the stack. When we match the first ")", is popped out of the stack, which is the sub-character between the two indices. String is the target string;

When

• matches a """, it will stop matching "(". It will not continue to search until the next """ is found. "(".

This is an algorithm that I came up with through brainstorming. If there are any shortcomings, please feel free to add.

//This way, try
/(([^()]*?"[^"()]*([^"()]+)[^()]*?"[^() ]*)+)|([^()]+)/

---

Added:

Analyze needs > Find solutions for each demand point > Integrate solutions = Solve problems

Analysis requirements:

1. needs to match the form of ( a )

2. There are two possibilities for the characters contained in a, represented by a1 and a2

   1. a1contains one or more strings in the form of b " c " b,

      1. where b is a string that does not include ", ( or )

      2. where c is a string that does not include "

   2. a2 does not contain ( or )

Reverse derivation:

2.2 => a2 = [^()]*
2.1.1 => b = [^()"]*
2.1.2 => c = [^"]*
2.1 => a1= (b"c"b)+ = (b"c")+b =([^()"]*"[^" ]*")+[^()"]*
1 => (a) = (a1)|(a2) = (([^()"]*"[^"]* ")+[^()"]*)|([^()]*)

Regular expression:

<code>/\(([^\(\)\"]*\"[^\"]*\")+[^\(\)\"]*\)|\([^\(\)]*\)/</code>

Verification:

<code class="javascript">var reg = /\(([^\(\)\"]*\"[^\"]*\")+[^\(\)\"]*\)|\([^\(\)]*\)/;

'(the (quick "brown" fox "jumps over, (the) lazy" dog ))'
    .match(reg)[0]
//"(quick "brown" fox "jumps over, (the) lazy" dog )"

'(the ("(quick)" brown fox "jumps (over, the)" lazy) dog )'
    .match(reg)[0];
//"("(quick)" brown fox "jumps (over, the)" lazy)"

'(the (quick brown fox (jumps "over", ((the) "lazy"))) dog )'
    .match(reg)[0];
//"(the)"</code>

Then change it like this:

<code>substr=str.match(/\([^()]+\)/g)[0]
</code>

Get the innermost bracket and the value in it, and then determine whether the first digit of the value is ", and whether the last digit is "":

<code>index=str.indexOf(str.match(/\([^()]+\)/g)[0])
length=str.match(/\([^()]+\)/g)[0].length
str.substr(index+length,1)
str.substr(index-1,1)
</code>

If it does not exist, it is the required answer. If it exists, replace substr in str first, then match it, and finally replace it back:

<code>str.replace(substr,"&&&")
str.replace(substr,"&&&").match(/\([^()]+\)/g)[0]
str.replace(substr,"&&&").match(/\([^()]+\)/g)[0].replace("&&&",substr)
</code>

本题难点在需要对""进行递归统计,例如

<code>(level_id = "D AND subject_id = "(Cat)"")</code>

(cat)是符合要求的.

<code>\([^()]*?\"((?:[^\"\"]|\"(?1)\")*+)\"[^()]*?\)|\([^()]*?\)
</code>

真爱生命,远离正则,该正则可以满足你的要求,php能用(php支持递归)java及Python无法使用.

推荐一个思路，找到（的index，切字符串处理

手机发不出正则 黑线
楼主的【^()】里如果不匹配()则继续
把不匹配(的条件去掉，把贪婪的+改成*?即可

!代码

console.log('(subject_id = “A” OR (status_id = “Open” AND (status_id = “C” OR level_id = “D”)))'.match(/(¹*)/))
希望对你有帮助

---

1. () ↩

用正则匹配会比较复杂，建议 把干扰串 "( 和 )" 替换掉，比如 "[， ]"，再用简单的正则替换，之后再换回来。

正则用 Python 实现如下：

<code>import re

str1 = '(subject_id = "A" OR (status_id = "Open" AND (status_id = "C" OR level_id = "D")))'
str2 = '(subject_id = "A" OR subject_id = "Food" OR (subject_id = "C" OR (status_id = "Open" AND (status_id = "C" OR (level_id = "D" AND subject_id = "(Cat)")))))'

pat = re.compile(r"""(?<=[^"])
        \([^()]+?
        ("\(.+?\)")*
        \)
        (?=[^"])
        """, re.X)

print pat.search(str1).group(0)
print pat.search(str2).group(0)</code>

输出为：

<code>(status_id = "C" OR level_id = "D")
(level_id = "D" AND subject_id = "(Cat)")
</code>