replaceFirst
fun replaceFirst(
input: CharSequence,
replacement: String
): String
(Common source) (JVM source) (JS source) (Native source)
For Common, JS, Native
Replaces the first occurrence of this regular expression in the specified input string with specified replacement expression.
The replacement string may contain references to the captured groups during a match. Occurrences of ${name}
or $index
in the replacement string will be substituted with the subsequences corresponding to the captured groups with the specified name or index.
In case of $index
, the first digit after '$' is always treated as a part of group reference. Subsequent digits are incorporated
into index
only if they would form a valid group reference. Only the digits '0'..'9' are considered as potential components
of the group reference. Note that indexes of captured groups start from 1, and the group with index 0 is the whole match.
In case of ${name}
, the name
can consist of latin letters 'a'..'z' and 'A'..'Z', or digits '0'..'9'. The first character must be
a letter.
Backslash character '\' can be used to include the succeeding character as a literal in the replacement string, e.g, \$
or \\
.
Regex.escapeReplacement can be used if replacement have to be treated as a literal string.
Parameters
input
- the char sequence to find a match of this regular expression in
replacement
- the expression to replace the found match with
Exceptions
RuntimeException
- if replacement expression is malformed, or capturing group with specified name
or index
does not exist
Return the result of replacing the first occurrence of this regular expression in input with the result of evaluating the replacement expression
For JVM
Replaces the first occurrence of this regular expression in the specified input string with specified replacement expression.
The replacement string may contain references to the captured groups during a match. Occurrences of ${name}
or $index
in the replacement string will be substituted with the subsequences corresponding to the captured groups with the specified name or index.
In case of $index
, the first digit after '$' is always treated as a part of group reference. Subsequent digits are incorporated
into index
only if they would form a valid group reference. Only the digits '0'..'9' are considered as potential components
of the group reference. Note that indexes of captured groups start from 1, and the group with index 0 is the whole match.
In case of ${name}
, the name
can consist of latin letters 'a'..'z' and 'A'..'Z', or digits '0'..'9'. The first character must be
a letter.
Backslash character '\' can be used to include the succeeding character as a literal in the replacement string, e.g, \$
or \\
.
Regex.escapeReplacement can be used if replacement have to be treated as a literal string.
Note that named capturing groups are supported in Java 7 or later.
Parameters
input
- the char sequence to find a match of this regular expression in
replacement
- the expression to replace the found match with
Exceptions
RuntimeException
- if replacement expression is malformed, or capturing group with specified name
or index
does not exist
Return the result of replacing the first occurrence of this regular expression in input with the result of evaluating the replacement expression