Regex

Common
JS
1.0
JVM
1.0
class Regex : Serializable
(source)
For JVM

Represents a compiled regular expression. Provides functions to match strings in text with a pattern, replace the found occurrences and split text around matches.

For pattern syntax reference see Pattern.

For JS

Represents a compiled regular expression. Provides functions to match strings in text with a pattern, replace the found occurrences and split text around matches.

For pattern syntax reference see MDN RegExp and http://www.w3schools.com/jsref/jsref_obj_regexp.asp.

Note that RegExp objects under the hood are constructed with the "u" flag that enables Unicode-related features in regular expressions. This also makes the pattern syntax more strict, for example, prohibiting unnecessary escape sequences.

Constructors

Common
JVM
JS
1.0

<init>

Creates a regular expression from the specified pattern string and the default options.

<init>(pattern: String)

Creates a regular expression from the specified pattern string and the specified single option.

<init>(pattern: String, option: RegexOption)

Creates a regular expression from the specified pattern string and the specified set of options.

<init>(pattern: String, options: Set<RegexOption>)

Properties

Common
JVM
JS
1.0

options

The set of options that were used to create this regular expression.

val options: Set<RegexOption>
Common
JVM
JS
1.0

pattern

The pattern string of this regular expression.

val pattern: String

Functions

Common
JVM
JS
1.0

containsMatchIn

Indicates whether the regular expression can find at least one match in the specified input.

fun containsMatchIn(input: CharSequence): Boolean
Common
JVM
JS
1.0

find

Returns the first match of a regular expression in the input, beginning at the specified startIndex.

fun find(
    input: CharSequence,
    startIndex: Int = 0
): MatchResult?
Common
JVM
JS
1.0

findAll

Returns a sequence of all occurrences of a regular expression within the input string, beginning at the specified startIndex.

fun findAll(
    input: CharSequence,
    startIndex: Int = 0
): Sequence<MatchResult>
Common
JVM
JS
1.7

matchAt

Attempts to match a regular expression exactly at the specified index in the input char sequence.

fun matchAt(input: CharSequence, index: Int): MatchResult?
Common
JVM
JS
1.0

matchEntire

Attempts to match the entire input CharSequence against the pattern.

fun matchEntire(input: CharSequence): MatchResult?
Common
JVM
JS
1.0

matches

Indicates whether the regular expression matches the entire input.

infix fun matches(input: CharSequence): Boolean
Common
JVM
JS
1.7

matchesAt

Checks if a regular expression matches a part of the specified input char sequence exactly at the specified index.

fun matchesAt(input: CharSequence, index: Int): Boolean
Common
JVM
JS
1.0

replace

Replaces all occurrences of this regular expression in the specified input string with specified replacement expression.

fun replace(input: CharSequence, replacement: String): String

Replaces all occurrences of this regular expression in the specified input string with the result of the given function transform that takes MatchResult and returns a string to be used as a replacement for that match.

fun replace(
    input: CharSequence,
    transform: (MatchResult) -> CharSequence
): String
Common
JVM
JS
1.0

replaceFirst

Replaces the first occurrence of this regular expression in the specified input string with specified replacement expression.

fun replaceFirst(
    input: CharSequence,
    replacement: String
): String
Common
JVM
JS
1.0

split

Splits the input CharSequence to a list of strings around matches of this regular expression.

fun split(input: CharSequence, limit: Int = 0): List<String>
Common
JVM
JS
1.6

splitToSequence

Splits the input CharSequence to a sequence of strings around matches of this regular expression.

fun splitToSequence(
    input: CharSequence,
    limit: Int = 0
): Sequence<String>
JVM
1.0

toPattern

Returns an instance of Pattern with the same pattern string and options as this instance of Regex has.

fun toPattern(): Pattern
JVM
JS
1.0

toString

Returns the string representation of this regular expression, namely the pattern of this regular expression.

fun toString(): String

Companion Object Functions

Common
JVM
JS
1.0

escape

Returns a regular expression pattern string that matches the specified literal string literally. No characters of that string will have special meaning when searching for an occurrence of the regular expression.

fun escape(literal: String): String
Common
JVM
JS
1.0

escapeReplacement

Returns a literal replacement expression for the specified literal string. No characters of that string will have special meaning when it is used as a replacement string in Regex.replace function.

fun escapeReplacement(literal: String): String
Common
JVM
JS
1.0

fromLiteral

Returns a regular expression that matches the specified literal string literally. No characters of that string will have special meaning when searching for an occurrence of the regular expression.

fun fromLiteral(literal: String): Regex