Append a character to a String in Kotlin

This article explores different ways to append a character at the end of a String in Kotlin. Since strings are immutable in Kotlin, the solution creates a new String instance.

1. Using `plus()` function

A simple solution to append characters to the end of a String is using the + (or +=) operator.

fun main() {

var str = "C"

val c = '#'

str = str + c

println(str) // C#

}

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Alternatively, we can use the plus() function to concatenate a char with the given string.

fun main() {

var str = "C"

val c = '#'

str = str.plus(c)

println(str) // C#

}

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2. Using String templates

Another concise solution to append a character to a string is with String templates. A template expression starts with a dollar sign ($) and consists of a name or an expression:

fun main() {

var str = "C"

val c = '#'

str = "$c$str"

println(str) // C#

}

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3. Using String builder

The idea here is to convert the string to a String builder and call its append() function to append a character. This logic would translate to the following code:

fun main() {

var str = "C"

val c = '+'

str = StringBuilder(str).append(c).append(c).toString()

println(str) // C++

}

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4. Using `String.format()` function

Finally, we can use the String.format() function to concatenate a character with a string. This is demonstrated below:

fun main() {

var str = "C"

val c = '#'

str = String.format("%s%c", str, c)

println(str) // C#

}

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That’s all about appending a character to the end of a String in Kotlin.

Append a character to a String in Kotlin

1. Using plus() function

2. Using String templates

3. Using String builder

4. Using String.format() function

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1. Using `plus()` function

4. Using `String.format()` function