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

时间:2021-11-30 15:18:20
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 parameter

The 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