javascript - Regex JS - 准确找到三个点

Question

我正在尝试找出三个点，不是 4 个，不是 2 个，只有 3 个。

例如:

• Hello world...(匹配)
• Hello World....(不匹配)
• .. (不匹配)
• >。 . . (不匹配)
• Hello World...是(匹配)
• Hello World...[Linkebreak](匹配项)

第一个开始是:

    return text.replace(/\.{3}/g, 'FOUND!');

但效果不是很好。有什么想法吗？

Answer 1

你想要的正则表达式:

/(^|[^.])\.{3}([^.]|$)/g

你想要的 JS 替换:

text.replace(/(^|[^.])\.{3}([^.]|$)/g, '$1FOUND!$2');

这是正则表达式的分解:

• (^|[^.]):没有字符 ^ 或 | 不是点的字符 [^. ]
• \.{3}:后跟三个点
• ([^.]|$) 后跟一个不是点 [^.] 或 | 的字符字符串 $
• $1:包含第一个捕获组
• $2:包括最后一个捕获组

此方法的唯一缺点是将跳过由单个字符分隔的 ... 的任何组合，因此您必须运行两次替换:

... ... ... ... ...   ... => FOUND!!! ... FOUND!!! ... FOUND!!!   FOUND!!!  

测试字符串:

"This should be found -> ... \
This should not be found -> .... \
Something will be found here -> .. .. ...... ... .. \
Multiple found -> ... ... .. ... ... .. \
... <- That's found \
Next line will be found \
..."

输出 1 次迭代:

"This should be found -> FOUND!
This should not be found -> ....
Something will be found here -> .. .. ...... FOUND! ..
Multiple found -> FOUND! ... .. FOUND! ... ..
FOUND! <- That's found
Next line will be found
FOUND!"

输出 2 次迭代:

"This should be found -> FOUND!
This should not be found -> ....
Something will be found here -> .. .. ...... FOUND! ..
Multiple found -> FOUND! FOUND! .. FOUND! FOUND! ..
FOUND! <- That's found
Next line will be found
FOUND!"