javascript 匹配字符串中的数字但不匹配百分比的正则表达式
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Regular expression that matches number in string but not percentages
提问by lorenzo-s
I need to know if there is a regular expression for testing for the presence of numbers in strings that:
我需要知道是否有用于测试字符串中是否存在数字的正则表达式：
- Matches
Lorem 20 Ipsum - Matches
Lorem 2,5 Ipsum - Matches
Lorem 20.5 Ipsum - Does notmatch
Lorem 2% Ipsum - Does notmatch
Lorem 20.5% Ipsum - Does notmatch
Lorem 20,5% Ipsum - Does notmatch
Lorem 2 percent Ipsum - Does notmatch
Lorem 20.5 percent Ipsum - Does notmatch
Lorem 20,5 percent Ipsum - Matches
Lorem 20 Ipsum 2% dolor - Matches
Lorem 2,5 Ipsum 20.5% dolor - Matches
Lorem 20.5 Ipsum 20,5% dolor
- 火柴
Lorem 20 Ipsum - 火柴
Lorem 2,5 Ipsum - 火柴
Lorem 20.5 Ipsum - 难道不匹配
Lorem 2% Ipsum - 难道不匹配
Lorem 20.5% Ipsum - 难道不匹配
Lorem 20,5% Ipsum - 难道不匹配
Lorem 2 percent Ipsum - 难道不匹配
Lorem 20.5 percent Ipsum - 难道不匹配
Lorem 20,5 percent Ipsum - 火柴
Lorem 20 Ipsum 2% dolor - 火柴
Lorem 2,5 Ipsum 20.5% dolor - 火柴
Lorem 20.5 Ipsum 20,5% dolor
That is, a regular expression that can tell me if in a string there is one or many numbers, but not as percentage value.
也就是说，一个正则表达式可以告诉我在一个字符串中是否有一个或多个数字，但不能作为百分比值。
I've tried something as /[0-9\.,]+[^%]/, but this not seems to work, I think because digits then not a percentage signmatch also the 20in the string 20%. Additionally, I don't know how to tell not the entire percentstringin addition to the %char.
我已经尝试了一些东西/[0-9\.,]+[^%]/，但这似乎不起作用，我认为因为数字然后不是百分比符号也匹配20字符串中的20%。此外，我不知道除了字符之外如何分辨整个percent字符串%。
回答by Rob Raisch
This will do what you need:
这将满足您的需求：
\b -- word boundary
\d+ -- one or more digits
(?:\.\d+)? -- optionally followed by a period and one or more digits
\b -- word boundary
\s+ -- one or more spaces
(?!%|percent) -- NOT followed by a % or the word 'percent'
--EDIT--
- 编辑 -
The meat here is the use of a "negative lookahead" on the final line that causes the match to fail if any of a percent-sign or the literal "percent" occurs after a number and one or more spaces. Other uses of negative lookahead in JavaScript RegExps can be found at Negative lookahead Regular Expression
这里的主要内容是在最后一行使用“负前瞻”，如果在数字和一个或多个空格之后出现任何百分号或文字“百分比”，则会导致匹配失败。在 JavaScript RegExps 中负前瞻的其他用法可以在负前瞻正则表达式中找到
--2ND EDIT-- Congrats to Enrico for solving the most general case but while his solution below is correct, it contains several extraneous operators. Here is the most succinct solution.
--第二次编辑--祝贺 Enrico 解决了最一般的情况，虽然他的解决方案是正确的，但它包含几个无关的运算符。这是最简洁的解决方案。
( -- start capture
\d+ -- one or more digits
(?:[\.,]\d+)? -- optional period or comma followed by one or more digits
\b -- word boundary
(?! -- start negative lookahead
(?:[\.,]\d+) -- must not be followed by period or comma plus digits
| -- or
(?: -- start option group
\s?% -- optional space plus percent sign
| -- or
\spercent -- required space and literal 'percent'
) -- end option group
) -- end negative lookahead
) -- end capture group
回答by enrico.bacis
This is the robust way to do it, and it's also extracting the numbers.
这是做到这一点的可靠方法，而且它还可以提取数字。
(\b\d+(?:[\.,]\d+)?\b(?!(?:[\.,]\d+)|(?:\s*(?:%|percent))))
It is similar to Rob's regex but it should work for all the cases.
它类似于 Rob 的正则表达式，但它应该适用于所有情况。
( -- capturing block
\b -- word boundary
\d+ -- one or more digits
(?:[\.,]\d+)? -- optionally followed by a period or a comma
and one or more digits
\b -- word boundary
(?! -- not followed by
(?:[\.,]\d+) -- a period or a comma and one or more digits
[that is the trick]
| -- or
(?:\s*(?:%|percent)) -- zero or more spaces and the % sign or 'percent'
)
)
回答by Bergi
Use negative lookaheadinstead of your negated character class:
使用否定前瞻代替否定字符类：
/\d+(?:[,.]\d+)?(?!\s*(?:percent|%))/
