javascript - 正则表达式匹配最里层括号的内容
str1 = '(subject_id = "A" OR (status_id = "Open" AND (status_id = "C" OR level_id = "D")))'
或者
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)")))))'
我需要通过正则,匹配字符串中最里层的括号及其中的内容(不匹配引号内的括号),即:
str1 => (status_id = "C" OR level_id = "D")
str2 => (level_id = "D" AND subject_id = "(Cat)")
那么,这种超复杂的正则应该怎么写?
如果正则实现不了,那么JS怎么来实现?
补充,对于 str1
,我找到了这样的正则可以满足匹配:
\([^()]+\)
但是对于str2, 依然没有办法,期待大家解答!
回复内容:
现在有一个字符串:
str1 = '(subject_id = "A" OR (status_id = "Open" AND (status_id = "C" OR level_id = "D")))'
或者
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)")))))'
我需要通过正则,匹配字符串中最里层的括号及其中的内容(不匹配引号内的括号),即:
str1 => (status_id = "C" OR level_id = "D")
str2 => (level_id = "D" AND subject_id = "(Cat)")
那么,这种超复杂的正则应该怎么写?
如果正则实现不了,那么JS怎么来实现?
补充,对于 str1
,我找到了这样的正则可以满足匹配:
\([^()]+\)
但是对于str2, 依然没有办法,期待大家解答!
对于str2,我找到了这样的
\([^()]*\"[^"]*\"[^()]*\)
看了一下需求我根本没考虑用正则,好像太复杂了...直接上传统方法吧;
可以使用运算优先级的思想,即用栈的数据结构来取得内部括号的内容;
技术要点:
匹配最内层的括号
引号内的内容不作为匹配标准
照着这个思路开始设计算法:
该算法是计算出要匹配的子字符串的 startIndex
和 endIndex
然后用 substring()
方法获得子字符串;
当匹配到一个
"("
字符的时,入栈,当我们匹配到第一个")"
时,出栈,即两个索引之间的子字符串为目标字符串;匹配到一个
"\""
时,则停止匹配"("
,直到搜索到下一个"\""
时,才继续开始搜索"("
。
拍脑袋想出来的算法,有不足之处欢迎补充。
//这样,试试/\(([^\(\)]*?"[^\"\(\)]*([^\"\(\)]+\)[^\(\)]*?\"[^\(\)]*)+)|([^\(\)]+\)/
补充:
分析需求 > 找到每个需求点的解决方案 > 整合解决方案 = 解决问题
分析需求:
需要匹配
( a )
的形式-
其中
a
包含的字符有两种可能,用a1
和a2
表示-
a1
含有一个或多个b " c " b
形式的字符串,其中
b
是一段不包括"
,(
或)
的字符串其中
c
是一段不包括"
的字符串
a2
中不含有(
或)
-
逆向推导:
2.2 =>
a2
=[^\(\)]*
2.1.1 =>b
=[^\(\)\"]*
2.1.2 =>c
=[^\"]*
2.1 =>a1
=(b\"c\"b)+
=(b\"c\")+b
=([^\(\)\"]*\"[^\"]*\")+[^\(\)\"]*
1 =>\(a\)
=\(a1\)|\(a2\)
=\(([^\(\)\"]*\"[^\"]*\")+[^\(\)\"]*\)|\([^\(\)]*\)
正则表达式:
/\(([^\(\)\"]*\"[^\"]*\")+[^\(\)\"]*\)|\([^\(\)]*\)/
验证:
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)"
那就这么改:
substr=str.match(/\([^()]+\)/g)[0]
得到最里面括号及其中的值,后判断该值前一位是否是 “,后一位是否是 ”:
index=str.indexOf(str.match(/\([^()]+\)/g)[0])
length=str.match(/\([^()]+\)/g)[0].length
str.substr(index+length,1)
str.substr(index-1,1)
如果不存在,则是需要的答案,如果存在,则先将str中substr替换掉,后在match一下,最后在替换回来:
str.replace(substr,"&&&")
str.replace(substr,"&&&").match(/\([^()]+\)/g)[0]
str.replace(substr,"&&&").match(/\([^()]+\)/g)[0].replace("&&&",substr)
本题难点在需要对""进行递归统计,例如
(level_id = "D AND subject_id = "(Cat)"")
(cat)是符合要求的.
\([^()]*?\"((?:[^\"\"]|\"(?1)\")*+)\"[^()]*?\)|\([^()]*?\)
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
- () ↩
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:
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"""(?
输出为:
(status_id = "C" OR level_id = "D")
(level_id = "D" AND subject_id = "(Cat)")