Kotlin List distinct()
Syntax & Examples

Syntax of List.distinct()

The syntax of List.distinct() extension function is:

fun <T> Iterable<T>.distinct(): List<T>

This distinct() extension function of List returns a list containing only distinct elements from the given collection.

✐ Examples

1 Example

In this example,

We create a list named list1 containing the characters 'a', 'p', 'p', 'l', 'e'.
We apply the distinct() function to list1 to get a new list distinctList containing only unique elements.
The resulting list distinctList contains elements 'a', 'p', 'l', 'e', as duplicates are removed.
Finally, we print the distinctList to standard output using print statement.

Kotlin Program

fun main(args: Array<String>) {
    val list1 = listOf(&quot;a&quot;, &quot;p&quot;, &quot;p&quot;, &quot;l&quot;, &quot;e&quot;);
    val distinctList = list1.distinct();
    print(distinctList);
}

Output

[a, p, l, e]

2 Example

In this example,

We create a list named list1 containing the integers 10, 20, 30, 10, 20.
We apply the distinct() function to list1 to get a new list distinctList containing only unique elements.
The resulting list distinctList contains elements 10, 20, 30, with duplicates removed.
Finally, we print the distinctList to standard output using print statement.

Kotlin Program

fun main(args: Array<String>) {
    val list1 = listOf(10, 20, 30, 10, 20);
    val distinctList = list1.distinct();
    print(distinctList);
}

Output

[10, 20, 30]

3 Example

In this example,

We create a list named list1 containing the strings 'apple', 'banana', 'mango', 'apple', 'banana'.
We apply the distinct() function to list1 to get a new list distinctList containing only unique elements.
The resulting list distinctList contains elements 'apple', 'banana', 'mango', with duplicates removed.
Finally, we print the distinctList to standard output using print statement.

Kotlin Program

fun main(args: Array<String>) {
    val list1 = listOf(&quot;apple&quot;, &quot;banana&quot;, &quot;mango&quot;, &quot;apple&quot;, &quot;banana&quot;);
    val distinctList = list1.distinct();
    print(distinctList);
}

Output

[apple, banana, mango]

Summary

In this Kotlin tutorial, we learned about distinct() extension function of List: the syntax and few working examples with output and detailed explanation for each example.