正则表达式查找带有可选空格的字符串 [英] Regex to find string with optional spaces

问题描述

我正在尝试验证字符串是否具有值

I'm trying to validate that a string has the values

edit=yes
edit = yes
edit= yes
edit =yes
edit=yesonce
edit = yesonce
edit= yesonce
edit =yesonce

到目前为止我在 edit=yes 上的匹配，但仅此而已.我认为我的可选空格参数是错误的，但不确定如何.

What I have so far matches on edit=yes but nothing more. I think my optional spaces arguments are wrong but not sure how.

edit[/s]?=[/s]?[yes|yesonce]

推荐答案

试试这个:

edit\s?=\s?yes(once)?

正则表达式的问题:

• 空格是 \s，而不是 /s - 转义字符是反斜杠，而不是斜杠.
• 在单个字符(或转义实体)周围不需要 []
• [yes|yesonce] 表示任意一个字符 y e s |y e s o n c e，而不是 yes 或 yesonce.
• 您的意思是 (yes|yesonce)，尽管它总是与 yes 匹配，并且不会在 yes 之后捕获 once 匹配.您可以改用 (yesonce|yes) 来避免这种情况，但是..
• yes(once)? 更简单 :)

• Whitespace is \s, not /s - the escape character is backslash, not slash.
• You don't need [] around a single character (or escaped entity)
• [yes|yesonce] means any one of the characters y e s | y e s o n c e, not either yes or yesonce.
• You meant (yes|yesonce), although that would always match yes, and not capture the once after the yes was matched. You could use (yesonce|yes) instead to avoid this, but..
• yes(once)? is simpler :)

如果你打算允许任意数量的空格，而不是一个或没有，你需要用 * 替换适当的 ? 符号(零或一")(包括零在内的任何数字"):

If you intended to allow any number of spaces, rather than one or none, you need to replace the appropriate ? symbols ("zero or one") with * ("any number including zero"):

edit\s*=\s*yes(once)?

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