【JavaScript】正则表达式--String.replace()变量替换的一点笔记

1234	var re = /(\w+)\s(\w+)/;var str = 'John Smith';var newstr = str.replace(re, '$2, $1');console.log(newstr); // Smith, John

$1

 

$2

是指被括号

()

包起来的

\w+

。
即当要使用变量替换时，

$n

指第n个用

()

包起来的表达式的值。
要用

()

包起来呀…‘(>﹏<)′ ‘(>﹏<)′Specifying a string as a parameterThe replacement string can include the following special replacement patterns:

Pattern	Inserts
$$	Inserts a “$”.
$&	Inserts the matched substring.
$`	Inserts the portion of the string that precedes the matched substring.
$’	Inserts the portion of the string that follows the matched substring.
$n	Where n is a non-negative integer lesser than 100, inserts the nth parenthesized submatch string, provided the first argument was a RegExp object.

Switching words in a string

About Sodino