Substitutions are regular expression language elements that are supported in replacement patterns.
| Pattern | Description | Sample | Replace | Input | Result |
| $ number | Substitutes the substring matched by group number. | \b(\w+)(\s)(\w+)\b | $3$2$1 | "one two" | "two one" |
| ${ name } | Substitutes the substring matched by the named group name. | \b(?\w+)(\s)(?\w+)\b | ${word2} ${word1} | "one two" | "two one" |
| $$ | Substitutes a literal "$". | \b(\d+)\s?USD | $$$1 | "103 USD" | "$103" |
| $& | Substitutes a copy of the whole match. | \$?\d*\.?\d+ | **$&** | "$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" |