Join Two Lists in Kotlin
In Kotlin, there are multiple ways to join lists.1. Using Plus Operator
A simple solution to join two lists is with the plus operator.import java.util.Arrays
fun <T> merge(first: List<T>, second: List<T>): List<T> {
return first + second
}
fun main() {
val fruits = listOf("Apple", "Banana")
val vegetables = listOf("Tomato", "Cucumber")
var list: List<String>? = merge(fruits, vegetables)
println(list)
}
Output
[Apple, Banana, Tomato, Cucumber]
2. Using plus() function
Another way we can join lists is to useplus()
function.import java.util.Arrays
fun <T> merge(first: List<T>, second: List<T>): List<T> {
return first.plus(second)
}
fun main() {
val fruits = listOf("Apple", "Banana")
val vegetables = listOf("Tomato", "Cucumber")
var list: List<String>? = merge(fruits, vegetables)
println(list)
}
Output
[Apple, Banana, Tomato, Cucumber]
3. Using addAll() function
Another way we can join lists is to useaddAll()
function.import java.util.Arrays
fun <T> merge(first: List<T>, second: List<T>): List<T> {
val list: MutableList<T> = ArrayList()
list.addAll(first)
list.addAll(second)
return list
}
fun main() {
val fruits = listOf("Apple", "Banana")
val vegetables = listOf("Tomato", "Cucumber")
var list: List<String>? = merge(fruits, vegetables)
println(list)
}
Output
[Apple, Banana, Tomato, Cucumber]