How to use the remove method of the HashSet in Kotlin

Overview

The remove method of the HashSet class can be used to remove the specific element from the set.

Syntax

fun remove(element: E): Boolean

Parameter

The method takes the element to be removed from the HashSet object as an argument.

Return value

This method returns true if the passed argument is removed from the set. If the element is not present in the set, then false is returned.

Code example

The below code demonstrates how to use the remove method:

fun main() {
//create a new HashSet which can have integer type as elements
var set: HashSet<Int> = hashSetOf<Int>()
// add three entries
set.add(1)
set.add(2)
set.add(3)
println("\nThe set is : $set")
println("\nset.remove(1):" + set.remove(1))
println("The set is : $set")
println("\nset.remove(5):" + set.remove(5))
println("The set is : $set")
}

Explanation

In the above code, we see the following:

  • Line 3: We create a new HashSet object with the name set. We use the hashSetOf() method to create an empty HashSet.

  • Lines 6 to 8: We add three new elements, (1,2,3), to the set using the add() method.

  • Line 11: We use the remove method of the set object to remove the element 1. The element 1 is present in the set. The element 1 is removed and true is returned as result. Now the set is [2,3].

  • Line 15: We use the remove method of the set object to remove the element 5. The element 5 is not present in the set. So, false is returned and set remains unchanged.

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