How to Remove Items from Set based on a Condition in Kotlin - Step by Step Examples

How to Remove Items from Set based on a Condition in Kotlin ?

Answer

To remove items from a set based on a condition in Kotlin, you can use the removeIf() method available for mutable sets.

✐ Examples

1 Remove Even Numbers from a Set

In this example,

First, we create a mutable set of integers named numberSet with values val numberSet = mutableSetOf(1, 2, 3, 4, 5).
Next, we use the removeIf() method on numberSet to remove even numbers.
The removeIf() method removes elements from the set for which the given predicate returns true.
We define a predicate using a lambda expression that checks if the element is even using the % operator.
We print the updated set to verify that even numbers have been removed.

Kotlin Program

fun main() {
    val numberSet = mutableSetOf(1, 2, 3, 4, 5)
    println("Original Set: $numberSet")
    numberSet.removeIf { it % 2 == 0 }
    println("Set after removing even numbers: $numberSet")
}

Output

Original Set: [1, 2, 3, 4, 5]
Set after removing even numbers: [1, 3, 5]

2 Remove Strings Longer Than 4 Characters from a Set

In this example,

First, we create a mutable set of strings named stringSet with values val stringSet = mutableSetOf("apple", "banana", "orange", "kiwi").
Next, we use the removeIf() method on stringSet to remove strings longer than 4 characters.
The removeIf() method removes elements from the set for which the given predicate returns true.
We define a predicate using a lambda expression that checks the length of the string using the length property.
We print the updated set to verify that strings longer than 4 characters have been removed.

Kotlin Program

fun main() {
    val stringSet = mutableSetOf("apple", "banana", "orange", "kiwi")
    println("Original Set: $stringSet")
    stringSet.removeIf { it.length > 4 }
    println("Set after removing strings longer than 4 characters: $stringSet")
}

Output

Original Set: [apple, banana, orange, kiwi]
Set after removing strings longer than 4 characters: [kiwi, apple]

Summary

In this tutorial, we learned How to Remove Items from Set based on a Condition in Kotlin language with well detailed examples.

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