kotlin-stdlib/kotlin.text/split

split

fun CharSequence.split(vararg delimiters: String, ignoreCase: Boolean = false, limit: Int = 0): List<String>(source)

Splits this char sequence to a list of strings around occurrences of the specified delimiters.

Since Kotlin

1.0

Parameters

delimiters

One or more strings to be used as delimiters.

ignoreCase

true to ignore character case when matching a delimiter. By default false.

limit

The maximum number of substrings to return. Zero by default means no limit is set.

To avoid ambiguous results when strings in delimiters have characters in common, this method proceeds from the beginning to the end of this string, and matches at each position the first element in delimiters that is equal to a delimiter in this instance at that position.

Samples

import java.util.Locale
import java.util.regex.Pattern
import kotlin.test.*

fun main() { 
   //sampleStart 
   val multiCharDelimiter = "apple--banana--cherry".split("--")
println(multiCharDelimiter) // [apple, banana, cherry]

val multipleSplit = "apple->banana;;cherry:::orange".split("->", ";;", ":::")
println(multipleSplit) // [apple, banana, cherry, orange]

val longerDelimiterFirst = "apple<-banana<--cherry".split("<--", "<-")
println(longerDelimiterFirst) // [apple, banana, cherry]

val shorterDelimiterFirst = "apple<-banana<--cherry".split("<-", "<--")
println(shorterDelimiterFirst) // [apple, banana, -cherry]

val limitSplit = "a->b->c->d->e".split("->", limit = 3)
println(limitSplit) // [a, b, c->d->e]

val emptyInputResult = "".split("sep")
println("emptyInputResult == listOf(\"\") is ${emptyInputResult == listOf("")}") // true

val emptyDelimiterSplit = "abc".split("")
println(emptyDelimiterSplit) // [, a, b, c, ]

val mixedCase = "abcXYZdef".split("xyz")
println(mixedCase) // [abcXYZdef]  // No match with case sensitivity

val mixedCaseIgnored = "abcXYZdef".split("xyz", ignoreCase = true)
println(mixedCaseIgnored) // [abc, def]  // Matches with case insensitivity

val emptyResults = "##a##b##c##".split("##")
println(emptyResults) // [, a, b, c, ]

val consecutiveSeparators = "a--b------c".split("--")
println(consecutiveSeparators) // [a, b, , , c] 
   //sampleEnd
}
fun CharSequence.split(vararg delimiters: Char, ignoreCase: Boolean = false, limit: Int = 0): List<String>(source)

Splits this char sequence to a list of strings around occurrences of the specified delimiters.

Since Kotlin

1.0

Parameters

delimiters

One or more characters to be used as delimiters.

ignoreCase

true to ignore character case when matching a delimiter. By default false.

limit

The maximum number of substrings to return.

Samples

import java.util.Locale
import java.util.regex.Pattern
import kotlin.test.*

fun main() { 
   //sampleStart 
   val commaSplit = "apple,banana,cherry".split(',')
println(commaSplit) // [apple, banana, cherry]

val charSplit = "apple,banana;cherry".split(',', ';')
println(charSplit) // [apple, banana, cherry]

val limitSplit = "a,b,c,d,e".split(',', limit = 3)
println(limitSplit) // [a, b, c,d,e]

val emptyInputResult = "".split('|')
println("emptyInputResult == listOf(\"\") is ${emptyInputResult == listOf("")}") // true

val mixedCase = "abcXdef".split('x')
println(mixedCase) // [abcXdef]  // No match with case sensitivity

val mixedCaseIgnored = "abcXdef".split('x', ignoreCase = true)
println(mixedCaseIgnored) // [abc, def]  // Matches with case insensitivity

val emptyResults = ",a,b,c,".split(',')
println(emptyResults) // [, a, b, c, ]

val consecutiveSeparators = "a,,b,,,c".split(',')
println(consecutiveSeparators) // [a, , b, , , c] 
   //sampleEnd
}
inline fun CharSequence.split(regex: Regex, limit: Int = 0): List<String>(source)

Splits this char sequence to a list of strings around matches of the given regular expression.

Since Kotlin

1.0

Parameters

limit

Non-negative value specifying the maximum number of substrings to return. Zero by default means no limit is set.

Samples

import java.util.Locale
import java.util.regex.Pattern
import kotlin.test.*

fun main() { 
   //sampleStart 
   val digitSplit = "apple123banana456cherry".split(Regex("\\d+"))
println(digitSplit) // [apple, banana, cherry]

val wordBoundarySplit = "The quick brown fox".split(Regex("\\s+"))
println(wordBoundarySplit) // [The, quick, brown, fox]

val limitSplit = "a,b,c,d,e".split(Regex(","), limit = 3)
println(limitSplit) // [a, b, c,d,e]

val patternGroups = "abc-123def_456ghi".split(Regex("[\\-_]\\d+"))
println(patternGroups) // [abc, def, ghi]

val caseInsensitiveSplit = "Apple123Banana45CHERRY".split(Regex("[a-z]+", RegexOption.IGNORE_CASE))
println(caseInsensitiveSplit) // [, 123, 45, ]

val emptyInputResult = "".split(Regex("sep"))
println("emptyInputResult == listOf(\"\") is ${emptyInputResult == listOf("")}") // true

val emptyDelimiterSplit = "abc".split(Regex(""))
println(emptyDelimiterSplit) // [, a, b, c, ]

val splitByMultipleSpaces = "a  b    c".split(Regex("\\s+"))
println(splitByMultipleSpaces) // [a, b, c]

val splitBySingleSpace = "a  b    c".split(Regex("\\s"))
println(splitBySingleSpace) // [a, , b, , , , c] 
   //sampleEnd
}
fun CharSequence.split(regex: Pattern, limit: Int = 0): List<String>(source)

Splits this char sequence around matches of the given regular expression.

This function has two notable differences from the method Pattern.split:

  • the function returns the result as a List<String> rather than an Array<String>;

  • when the limit is not specified or specified as 0, this function doesn't drop trailing empty strings from the result.

Since Kotlin

1.0

Parameters

limit

Non-negative value specifying the maximum number of substrings to return. Zero by default means no limit is set.

Samples

import java.util.Locale
import java.util.regex.Pattern
import kotlin.test.*

fun main() { 
   //sampleStart 
   val digitSplit = "apple123banana456cherry".split(Pattern.compile("\\d+"))
println(digitSplit) // [apple, banana, cherry]

val wordBoundarySplit = "The quick brown fox".split(Pattern.compile("\\s+"))
println(wordBoundarySplit) // [The, quick, brown, fox]

val limitSplit = "a,b,c,d,e".split(Pattern.compile(","), limit = 3)
println(limitSplit) // [a, b, c,d,e]

val patternGroups = "abc-123def_456ghi".split(Pattern.compile("[\\-_]\\d+"))
println(patternGroups) // [abc, def, ghi]

val caseInsensitiveSplit = "Apple123Banana45CHERRY".split(Pattern.compile("[a-z]+", Pattern.CASE_INSENSITIVE))
println(caseInsensitiveSplit) // [, 123, 45, ]

val emptyInputResult = "".split(Pattern.compile("sep"))
println("emptyInputResult == listOf(\"\") is ${emptyInputResult == listOf("")}") // true

val emptyDelimiterSplit = "abc".split(Pattern.compile(""))
println(emptyDelimiterSplit) // [a, b, c, ]

val splitByMultipleSpaces = "a  b    c".split(Pattern.compile("\\s+"))
println(splitByMultipleSpaces) // [a, b, c]

val splitBySingleSpace = "a  b    c".split(Pattern.compile("\\s"))
println(splitBySingleSpace) // [a, , b, , , , c] 
   //sampleEnd
}