kotlin filternot
The filterNot
function in Kotlin is used to filter a collection based on a provided predicate. It returns a new list containing all the elements for which the predicate returns false. Here is an explanation of each step involved in using the filterNot
function:
- Import the required packages: Make sure to import the necessary packages to use the
filterNot
function. You can import it using the following statement:
kotlin
import kotlin.collections.filterNot
- Create a collection: Create a collection of elements that you want to filter. This can be a list, set, or any other type of collection. For example, let's create a list of numbers:
kotlin
val numbers = listOf(1, 2, 3, 4, 5)
- Define the predicate: Define a predicate that specifies the condition for filtering the elements. The predicate is a lambda expression that takes an element as its argument and returns a Boolean value indicating whether the element should be included in the filtered list. For example, let's define a predicate that filters out even numbers:
kotlin
val predicate: (Int) -> Boolean = { number -> number % 2 != 0 }
In this case, the predicate checks if the number is not divisible by 2, which means it is an odd number.
- Use the
filterNot
function: Apply thefilterNot
function on the collection and pass the predicate as an argument. The function will return a new list containing all the elements for which the predicate returns false. For example, let's filter thenumbers
list using the defined predicate:
kotlin
val filteredNumbers = numbers.filterNot(predicate)
The filteredNumbers
list will contain all the odd numbers from the numbers
list.
- Access the filtered elements: You can now access the filtered elements in the
filteredNumbers
list and perform further operations on them. For example, you can print the filtered numbers:
kotlin
for (number in filteredNumbers) {
println(number)
}
This will print the odd numbers from the numbers
list.
That's it! You have now learned how to use the filterNot
function in Kotlin to filter a collection based on a predicate.