Kotlin – Set Element of Array at Specific Index

To set an element of Array with a new value at specified index in Kotlin language, use Array.set() method. Call set() method on this array and pass the index and new value as arguments.

Syntax

The syntax to call set() method on Array arr with index I and new value value passed as argument is

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arr.set(i, value)

Examples

In the following program, we take an array of strings, and set the element at index 2 with new value "guava" using Array.set() method.

Main.kt

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fun main(args: Array<String>) {
    val arr = arrayOf("apple", "banana", "cherry", "mango")
    arr.set(2, "guava")
    arr.forEach {
        println(it)
    }
}

Output

apple
banana
guava
mango

If the index specified is out of bounds for the given array, then set() throws ArrayIndexOutOfBoundsException.

In the following program, we take an array of strings, and set the element at index 5 of the array arr. Since arr is only of size 4, set() throws ArrayIndexOutOfBoundsException.

Main.kt

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fun main(args: Array<String>) {
    val arr = arrayOf("apple", "banana", "cherry", "mango")
    arr.set(5, "guava")
    arr.forEach {
        println(it)
    }
}

Output

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: Index 5 out of bounds for length 4
	at MainKt.main(Main.kt:3)

Conclusion

In this Kotlin Tutorial, we learned how to set element of an Array with new value at specified index, using Array.set() method, in Kotlin programming language with examples.