替換被用於替換模式。下表列出了取代常見類型：

字符	描述	模式	替換模式	輸入字符串	輸出字符串
$number	替換匹配的組號子字符串	(w+)(s)(w+)	$3$2$1	"one two"	"two one"
${name}	替代匹配命名子字符串groupname.	(?< word1>w+)(s)(?< word2>w+)	${word2} ${word1}	"one two"	"two one"
$$	替代文字 "$".	(d+)s?USD	$$$1	"103 USD"	"$103"
$&	替代了整體匹配的一個副本	($*(d*(.+d+)?){1})	**$&	"$1.30"	"**$1.30**"
$`	Substitutes all the text of the input string before the match.	B+	$`	"AABBCC"	"AAAACC"
$'	Substitutes all the text of the input string after the match.	B+	$'	"AABBCC"	"AACCCC"
$+	Substitutes the last group that was captured.	B+(C+)	$+	"AABBCCDD"	AACCDD
$_	Substitutes the entire input string.	B+	$_	"AABBCC"	"AAAABBCCCC"