有没有人可以帮我解释这个正则表达式？
var regex = /<a\s+([^>]+\s+)?href\s*=\s*('([^']*)'|"([^"]*)|([^\s>]+))[^>]*>/g;
答案 0 :(得分：4)
<强> Regex Explnation
NODE EXPLANATION
--------------------------------------------------------------------------------
<a '<a'
--------------------------------------------------------------------------------
\s+ whitespace (\n, \r, \t, \f, and " ") (1 or
more times (matching the most amount
possible))
--------------------------------------------------------------------------------
( group and capture to \1 (optional
(matching the most amount possible)):
--------------------------------------------------------------------------------
[^>]+ any character except: '>' (1 or more
times (matching the most amount
possible))
--------------------------------------------------------------------------------
\s+ whitespace (\n, \r, \t, \f, and " ") (1
or more times (matching the most amount
possible))
--------------------------------------------------------------------------------
)? end of \1 (NOTE: because you are using a
quantifier on this capture, only the LAST
repetition of the captured pattern will be
stored in \1)
--------------------------------------------------------------------------------
href 'href'
--------------------------------------------------------------------------------
\s* whitespace (\n, \r, \t, \f, and " ") (0 or
more times (matching the most amount
possible))
--------------------------------------------------------------------------------
= '='
--------------------------------------------------------------------------------
\s* whitespace (\n, \r, \t, \f, and " ") (0 or
more times (matching the most amount
possible))
--------------------------------------------------------------------------------
( group and capture to \2:
--------------------------------------------------------------------------------
' '\''
--------------------------------------------------------------------------------
( group and capture to \3:
--------------------------------------------------------------------------------
[^']* any character except: ''' (0 or more
times (matching the most amount
possible))
--------------------------------------------------------------------------------
) end of \3
--------------------------------------------------------------------------------
' '\''
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
" '"'
--------------------------------------------------------------------------------
( group and capture to \4:
--------------------------------------------------------------------------------
[^"]* any character except: '"' (0 or more
times (matching the most amount
possible))
--------------------------------------------------------------------------------
) end of \4
--------------------------------------------------------------------------------
| OR
--------------------------------------------------------------------------------
( group and capture to \5:
--------------------------------------------------------------------------------
[^\s>]+ any character except: whitespace (\n,
\r, \t, \f, and " "), '>' (1 or more
times (matching the most amount
possible))
--------------------------------------------------------------------------------
) end of \5
--------------------------------------------------------------------------------
) end of \2
--------------------------------------------------------------------------------
[^>]* any character except: '>' (0 or more times
(matching the most amount possible))
--------------------------------------------------------------------------------
> '>'