5 different examples to split a string in Kotlin

How to split a string in Kotlin:

In this post, we will learn different ways to split a string in Kotlin. Kotlin provides an inbuilt method to split a string. We can use a delimeter or a regular expression to split a string. Let’s learn how to split a string in different ways in Kotlin.

Definition of split:

Kotlin provides an inbuilt method split to split a string. We can pass a character or a string as its delimeter. It returns a list of strings, i.e. the split result.

It is defined as:

str.split(vararg delimiters: Char, ignoreCase: Boolean = false, limit: Int = 0): List<String>

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

Here,

delimiters is one or more strings or characters to use as the delimiter.
ignoreCase is used to define if we are ignoring the character case or not while matching the delimiters. This is an optional value and it is false by default.
limit defines the maximum number of substrings to return by this method. This is also an optional value and it is 0 by default i.e. no limit is set for the split operation.

We can also pass a regular expression to the split method.

str.split(regex: Regex, limit: Int = 0): List<String>

It will split around matches of the regular expression regex. The second parameter limit is the maximum number of substrings to return by this method.

Example 1: Split a string by passing a single delimiter:

Let’s try to split a string by passing a single delimiter:

fun main() {
    val givenString = "one-two-three-four-five"

    val splittedString = givenString.split('-')

    println(splittedString)
}

We are passing the character - as the delimiter. It will print:

[one, two, three, four, five]

Similarly, let’s try it with a single string delimiter:

fun main() {
    val givenString = "one--two--three--four--five"

    val splittedString = givenString.split("--")

    println(splittedString)
}

It will print the same result:

[one, two, three, four, five]

Example 2: Split a string by passing multiple delimiters:

We can also pass multiple delimiters to the split function. It will split the string at any of these characters or strings:

fun main() {
    val givenString = "one-two/three?four=five"

    val splittedString = givenString.split('-', '/', '?', '=')

    println(splittedString)
}

This will split the givenString at any of -, /, ? or =. If you run this program, it will print:

[one, two, three, four, five]

Example 3: Split a string by ignoring character case:

We can pass ignoreCase as true to ignore the character case for the split operation. Let’s take a look at the below example:

fun main() {
    val givenString = "1break234Break567BREAK890bReaK11"

    val splittedString = givenString.split("break", ignoreCase = true)

    println(splittedString)
}

It splits the string at break by ignoring the character case of the word. It will print:

[1, 234, 567, 890, 11]

Example 4: Split a string with limit:

We can pass a limit value to specify the total number of substrings to return. For example:

fun main() {
    val givenString = "one-two-three-four-five-six"

    val splittedString = givenString.split('-', limit = 3)

    println(splittedString)
}

The limit is 3, so it will return three substrings:

[one, two, three-four-five-six]

Example 5: Split a string with a regular expression:

The following example will split a string with a regular expression:

fun main() {
    val givenString = "one1two2three3four4five5six6seven"

    val splittedString = givenString.split(Regex("\\d"))

    println(splittedString)
}

It is splilt in any number as the regular expression is matching any number value. It will match for 1, 2, 3, 4, 5, 6, 7, 8, or 9.

Output:

[one, two, three, four, five, six, seven]

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