Convert List of String to a String array in Kotlin

This post will discuss how to convert a list of strings to a string array in Kotlin.

1. Using `toTypedArray()` function

A simple solution to convert a list to a typed array is using the toTypedArray() function. The following solution demonstrates its usage by invoking the toTypedArray() function on List<String>, that results in an Array<String>.

fun main() {

val cities = listOf("Washington, D.C.", "Los Angeles", "Seattle")

val array = cities.toTypedArray()

println(array.contentToString())

}

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Output:

[Washington, D.C., Los Angeles, Seattle]

2. Naive solution

A naive solution allocates storage for the destination string array, and iterate over the list of strings to copy each element to its correct position in the string array. This can be implemented as follows in Kotlin.

fun main() {

val cities = listOf("Washington, D.C.", "Los Angeles", "Seattle")

// allocate storage for the string array

val array = arrayOfNulls<String>(cities.size)

// copy all the list elements to the string array

for (i in array.indices) {

array[i] = cities[i]

}

println(array.contentToString())

}

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Output:

[Washington, D.C., Los Angeles, Seattle]

That’s all about converting a List of String to an array of Kotlin String.

Convert List of String to a String array in Kotlin

1. Using toTypedArray() function

2. Naive solution

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1. Using `toTypedArray()` function