Split a String into chunks of given size in Kotlin

This article explores different ways to split a String into chunks of the given size in Kotlin.

1. Using `chunked()` function

The standard solution to split a String into a list of strings is using the chunked() function, where each string does not exceed the specified size. The following code example shows invocation for this method:

fun main() {

val s = "ABCDEFGHIJKLMNO"

val size = 5

val chunks = s.chunked(size)

println(chunks) // [ABCDE, FGHIJ, KLMNO]

}

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2. Using `substring()` function

Another option to partition a string into fixed-length chunks is using the substring() function. This would translate to a simple code below:

fun split(s: String, size: Int): List<String> {

val chunks = mutableListOf<String>()

var i = 0

while (i < s.length) {

chunks.add(s.substring(i, Math.min(s.length, i + size)))

i += size

}

return chunks

}

fun main() {

val s = "ABCDEFGHIJKLMNO"

val size = 5

println(split(s, size)) // [ABCDE, FGHIJ, KLMNO]

}

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3. Using Regex

Finally, we can split a string into equal size chinks around matches of the given regular expression. The following solution demonstrates this by creating a matcher and generate the start and the end index of each chunk.

import java.util.regex.Pattern

fun main() {

val s = "ABCDEFGHIJKLMNO"

val size = 5

val match = Pattern.compile(".{1,$size}").matcher(s)

val chunks = mutableListOf<String>()

while (match.find()) {

chunks.add(s.substring(match.start(), match.end()))

}

println(chunks) // [ABCDE, FGHIJ, KLMNO]

}

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That’s all about splitting a String into chunks of the given size in Kotlin.

Split a String into chunks of given size in Kotlin

1. Using chunked() function

2. Using substring() function

3. Using Regex

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1. Using `chunked()` function

2. Using `substring()` function