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

Jun 15, 2016 | Node.js

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