正则表达式 - 边界字符(^ 和 $)与转义字符(\A 和\Z)

Question

两者有什么区别

\A  Match at only beginning of string
\Z  Match at only end of string (or before newline at the end)

^   Match the beginning of the line
$   Match the end of the line (or before newline at the end)

Answer 1

来自 perl 文档(我在标准正则表达式语法中看不到它们):

The "\A" and "\Z" are just like "^" and "$", except that they won't match multiple times when the "/m" modifier is used, while "^" and "$" will match at every internal line boundary.

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