题
这是一个整洁的正则表达式,易于理解,维护和修改。
text = text.replace(/
( // Wrap whole match in $1
(
^[ \t]*>[ \t]? // '>' at the start of a line
.+\n // rest of the first line
(.+\n)* // subsequent consecutive lines
\n* // blanks
)+
)
/gm,
但是您如何使用这些?
text = text.replace(/((^[ \t]*>[ \t]?.+\n(.+\n)*\n*)+)/gm,
有没有 美丽 有意义的某种形式并描述了它的功能?
解决方案
Regexbuddy 将为您“翻译”任何正直。给您的示例正则赠送时,它会输出:
((^[ \t]*>[ \t]?.+\n(.+\n)*\n*)+)
Options: ^ and $ match at line breaks
Match the regular expression below and capture its match into backreference number 1 «((^[ \t]*>[ \t]?.+\n(.+\n)*\n*)+)»
Match the regular expression below and capture its match into backreference number 2 «(^[ \t]*>[ \t]?.+\n(.+\n)*\n*)+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Note: You repeated the capturing group itself. The group will capture only the last iteration.
Put a capturing group around the repeated group to capture all iterations. «+»
Assert position at the beginning of a line (at beginning of the string or after a line break character) «^»
Match a single character present in the list below «[ \t]*»
Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
The character “ ” « »
A tab character «\t»
Match the character “>” literally «>»
Match a single character present in the list below «[ \t]?»
Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
The character “ ” « »
A tab character «\t»
Match any single character that is not a line break character «.+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Match a line feed character «\n»
Match the regular expression below and capture its match into backreference number 3 «(.+\n)*»
Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
Note: You repeated the capturing group itself. The group will capture only the last iteration.
Put a capturing group around the repeated group to capture all iterations. «*»
Match any single character that is not a line break character «.+»
Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Match a line feed character «\n»
Match a line feed character «\n*»
Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
这确实以文本形式看起来很吓人,但是以HTML形式(在这里无法复制)或RegexBuddy本身更具可读性。它还指出了常见的陷阱(例如重复捕获的群体,这可能不想要这里)。
其他提示
值得一提的是熟练以一行形式读取正则表达式。大多数情况下是这样写的
我喜欢 Expresso
过了一会儿,我已经习惯了阅读这些东西。大多数Regexes都没有太多,我建议该网站 http://www.regular-expressions.info/ 如果您想更频繁地使用它们。
正则表达只是表达口罩等的一种方式。最后,它只是一种具有自己的语法的“语言”。
评论您的正则表达式的每一点都与评论项目的每一行相同。
当然,这将帮助那些不了解您的代码的人,但是如果您(开发人员)了解正则含义,那是没有用的。
对我来说,阅读正则表达式与阅读代码是相同的。如果表达确实很复杂,则下面的解释可能很有用,但是在大多数情况下,没有必要。
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